'\" t
.\"
.\" avrdude - A Downloader/Uploader for AVR device programmers
.\" Copyright (C) 2001, 2002, 2003, 2005 - 2020  Joerg Wunsch
.\"
.\" This program is free software; you can redistribute it and/or modify
.\" it under the terms of the GNU General Public License as published by
.\" the Free Software Foundation; either version 2 of the License, or
.\" (at your option) any later version.
.\"
.\" This program is distributed in the hope that it will be useful,
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
.\" GNU General Public License for more details.
.\"
.\" You should have received a copy of the GNU General Public License
.\" along with this program. If not, see <http://www.gnu.org/licenses/>.
.\"
.\"
.\" $Id$
.\"
.Dd July 12, 2022
.Os
.Dt AVRDUDE 1
.Sh NAME
.Nm avrdude
.Nd driver program for ``simple'' Atmel AVR MCU programmer
.Sh SYNOPSIS
.Nm
.Fl p Ar partno
.Op Fl b Ar baudrate
.Op Fl B Ar bitclock
.Op Fl c Ar programmer-id
.Op Fl C Ar config-file
.Op Fl A
.Op Fl D
.Op Fl e
.Oo Fl E Ar exitspec Ns
.Op \&, Ns Ar exitspec
.Oc
.Op Fl F
.Op Fl i Ar delay
.Op Fl l Ar logfile
.Op Fl n
.Op Fl O
.Op Fl P Ar port
.Op Fl q
.Op Fl t
.Op Fl U Ar memtype:op:filename:filefmt
.Op Fl v
.Op Fl x Ar extended_param
.Op Fl V
.Sh DESCRIPTION
.Nm Avrdude
is a program for downloading code and data to Atmel AVR
microcontrollers.
.Nm Avrdude
supports Atmel's STK500 programmer,
Atmel's AVRISP and AVRISP mkII devices,
Atmel's STK600,
Atmel's JTAG ICE (mkI, mkII and 3, the latter two also in ISP mode),
programmers complying to AppNote AVR910 and AVR109 (including the Butterfly),
as well as a simple hard-wired
programmer connected directly to a
.Xr ppi 4
or
.Xr parport 4
parallel port, or to a standard serial port.
In the simplest case, the hardware consists just of a
cable connecting the respective AVR signal lines to the parallel port.
.Pp
The MCU is programmed in
.Em serial programming mode ,
so, for the
.Xr ppi 4
based programmer, the MCU signals
.Ql /RESET ,
.Ql SCK ,
.Ql SDI
and
.Ql SDO
of the AVR's SPI interface need to be connected to the
parallel port; older boards might use the labels MOSI for SDO or MISO for SDI.
Optionally, some otherwise
unused output pins of the parallel port can be used to supply power
for the MCU part, so it is also possible to construct a passive
stand-alone programming device.  Some status LEDs indicating the
current operating state of the programmer can be connected, and a
signal is available to control a buffer/driver IC 74LS367 (or
74HCT367).  The latter can be useful to decouple the parallel port
from the MCU when in-system programming is used.
.Pp
A number of equally simple bit-bang programming adapters that connect
to a serial port are supported as well, among them the popular
Ponyprog serial adapter, and the DASA and DASA3 adapters that used to
be supported by uisp(1).
Note that these adapters are meant to be attached to a physical serial
port.
Connecting to a serial port emulated on top of USB is likely to not
work at all, or to work abysmally slow.
.Pp
If you happen to have a Linux system with at least 4 hardware GPIOs 
available (like almost all embedded Linux boards) you can do without 
any additional hardware - just connect them to the SDO, SDI, RESET
and SCK pins on the AVR and use the linuxgpio programmer type. It bitbangs
the lines using the Linux sysfs GPIO interface. Of course, care should
be taken about voltage level compatibility. Also, although not strictly
required, it is strongly advisable to protect the GPIO pins from 
overcurrent situations in some way. The simplest would be to just put
some resistors in series or better yet use a 3-state buffer driver like
the 74HC244. Have a look at http://kolev.info/blog/2013/01/06/avrdude-linuxgpio/ for a more
detailed tutorial about using this programmer type.
.Pp
Under a Linux installation with direct access to the SPI bus and GPIO
pins, such as would be found on a Raspberry Pi, the ``linuxspi''
programmer type can be used to directly connect to and program a chip
using the built in interfaces on the computer. The requirements to use
this type are that an SPI interface is exposed along with one GPIO
pin. The GPIO serves as the reset output since the Linux SPI drivers
do not hold chip select down when a transfer is not occurring and thus
it cannot be used as the reset pin. A readily available level
translator should be used between the SPI bus/reset GPIO and the chip
to avoid potentially damaging the computer's SPI controller in the
event that the chip is running at 5V and the SPI runs at 3.3V. The
GPIO chosen for reset can be configured in the avrdude configuration
file using the
.Li reset
entry under the linuxspi programmer, or
directly in the port specification. An external pull-up resistor
should be connected between the AVR's reset pin and Vcc. If Vcc is not
the same as the SPI voltage, this should be done on the AVR side of
the level translator to protect the hardware from damage.
.Pp
The
.Fl P Ar portname
option for this programmer defaults to
.Li /dev/spidev0.0:/dev/gpiochip0 .
.Pp
Atmel's STK500 programmer is also supported and connects to a serial
port.
Both, firmware versions 1.x and 2.x can be handled, but require a
different programmer type specification (by now).
Using firmware version 2, high-voltage programming is also supported,
both parallel and serial
(programmer types stk500pp and stk500hvsp).
.Pp
Wiring boards (e.g. Arduino Mega 2560 Rev3) are supported, utilizing STK500
V2.x protocol, but a simple DTR/RTS toggle is used to set the boards into
programming mode.  The programmer type is ``wiring''.  Note that the -D option
will likely be required in this case, because the bootloader will rewrite the
program memory, but no true chip erase can be performed.
.Pp
Serial bootloaders that run a skeleton of the STK500 1.x protocol are
supported via their own programmer type ``arduino''.  This programmer works
for the Arduino Uno Rev3 or any AVR that runs the Optiboot bootloader.
.Pp
Urprotocol is a leaner version of the STK500 1.x protocol that is designed
to be backwards compatible with STK500 v1.x, and allows bootloaders to be
much smaller, e.g., as implemented in the urboot project
https://github.com/stefanrueger/urboot. The programmer type ``urclock''
caters for these urboot programmers. Owing to its backward compatibility,
bootloaders that can be served by the arduino programmer can normally
also be served by the urclock programmer. This may require specifying the
size of (to avrdude) unknown bootloaders in bytes using the
.Fl x Ar bootsize=<n>
option, which is necessary for the urclock programmer to enable it to
protect the bootloader from being overwritten. If an unknown bootloader
has EEPROM read/write capability then the option -x eepromrw informs
avrdude -c urclock of that capability.
.Pp
The BusPirate is a versatile tool that can also be used as an AVR programmer.
A single BusPirate can be connected to up to 3 independent AVRs. See
the section on
.Em extended parameters
below for details.
.Pp
Atmel's STK600 programmer is supported in ISP and high-voltage
programming modes, and connects through the USB.
For ATxmega devices, the STK600 is supported in PDI mode.
For ATtiny4/5/9/10 devices, the STK600 and AVRISP mkII are supported in TPI mode.
.Pp
The simple serial programmer described in Atmel's application note
AVR910, and the bootloader described in Atmel's application note
AVR109 (which is also used by the AVR Butterfly evaluation board), are
supported on a serial port.
.Pp
Atmel's JTAG ICE (mkI, mkII, and 3) is supported as well to up- or download memory
areas from/to an AVR target (no support for on-chip debugging).
For the JTAG ICE mkII, JTAG, debugWire and ISP mode are supported, provided
it has a firmware revision of at least 4.14 (decimal).
JTAGICE3 also supports all of JTAG, debugWIRE, and ISP mode.
See below for the limitations of debugWire.
For ATxmega devices, the JTAG ICE mkII is supported in PDI mode, provided it
has a revision 1 hardware and firmware version of at least 5.37 (decimal).
For ATxmega devices, the JTAGICE3 is supported in PDI mode.
.Pp
Atmel-ICE (ARM/AVR) is supported in all modes (JTAG, PDI for Xmega, debugWIRE,
ISP, UPDI).
.Pp
Atmel's XplainedPro boards, using the EDBG protocol (CMSIS-DAP compatible),
are supported using the "jtag3" programmer type.
.Pp
Atmel's XplainedMini boards, using the mEDBG protocol,
are also supported using the "jtag3" programmer type.
.Pp
The AVR Dragon is supported in all modes (ISP, JTAG, HVSP, PP, debugWire).
When used in JTAG and debugWire mode, the AVR Dragon behaves similar to a
JTAG ICE mkII, so all device-specific comments for that device
will apply as well.
When used in ISP mode, the AVR Dragon behaves similar to an
AVRISP mkII (or JTAG ICE mkII in ISP mode), so all device-specific
comments will apply there.
In particular, the Dragon starts out with a rather fast ISP clock
frequency, so the
.Fl B Ar bitclock
option might be required to achieve a stable ISP communication.
For ATxmega devices, the AVR Dragon is supported in PDI mode, provided it
has a firmware version of at least 6.11 (decimal).
.Pp
The avrftdi, USBasp ISP and USBtinyISP adapters are also supported, provided
.Nm avrdude
has been compiled with libusb support.
USBasp ISP and USBtinyISP both feature simple firmware-only USB implementations, 
running on an ATmega8 (or ATmega88), or ATtiny2313, respectively. If libftdi has 
has been compiled in 
.Nm avrdude ,
the avrftdi device adds support for many programmers using FTDI's 2232C/D/H 
and 4232H parts running in MPSSE mode, which hard-codes (in the chip) 
SCK to bit 1, SDO to bit 2, and SDI to bit 3. Reset is usually bit 4.
.Pp
The Atmel DFU bootloader is supported in both, FLIP protocol version 1
(AT90USB* and ATmega*U* devices), as well as version 2 (Xmega devices).
See below for some hints about FLIP version 1 protocol behaviour.
.Pp
The MPLAB(R) PICkit 4 and MPLAB(R) SNAP, are supported in JTAG, TPI, ISP,
PDI and UPDI mode.
The Curiosity Nano board is supported in UPDI mode. It is dubbed
.Dq PICkit on Board ,
thus the name
.Pa pkobn_updi .
.Pp
SerialUPDI programmer implementation is based on Microchip's
.Em pymcuprog Li https://github.com/microchip-pic-avr-tools/pymcuprog
utility, but it also contains some performance improvements included in
Spence Konde's
.Em DxCore
Arduino core
.Li https://github.com/SpenceKonde/DxCore .
In a nutshell, this programmer consists of simple USB->UART adapter, diode
and couple of resistors. It uses serial connection to provide UPDI interface.
See the texinfo documentation for more details and known issues.
.Pp
The jtag2updi programmer is supported,
and can program AVRs with a UPDI interface.
Jtag2updi is just a firmware that can be uploaded to an AVR,
which enables it to interface with avrdude using the jtagice mkii protocol
via a serial link.
.Li https://github.com/ElTangas/jtag2updi
.Pp
The Micronucleus bootloader is supported for both protocol version V1
and V2. As the bootloader does not support reading from flash memory,
use the
.Fl V
option to prevent AVRDUDE from verifying the flash memory.
See the section on
.Em extended parameters
for Micronucleus specific options.
.Pp
The Teensy bootloader is supported for all AVR boards.
As the bootloader does not support reading from flash memory,
use the
.Fl V
option to prevent AVRDUDE from verifying the flash memory.
See the section on
.Em extended parameters
for Teensy specific options.
.Pp
Input files can be provided, and output files can be written in
different file formats, such as raw binary files containing the data
to download to the chip, Intel hex format, or Motorola S-record
format.  There are a number of tools available to produce those files,
like
.Xr asl 1
as a standalone assembler, or
.Xr avr-objcopy 1
for the final stage of the GNU toolchain for the AVR microcontroller.
.Pp
Provided
.Xr libelf 3
was present when compiling
.Nm avrdude ,
the input file can also be the final ELF file as produced by the linker.
The appropriate ELF section(s) will be examined, according to the memory
area to write to.
.Pp
.Nm Avrdude
can program the EEPROM and flash ROM memory cells of supported AVR
parts.  Where supported by the serial instruction set, fuse bits and
lock bits can be programmed as well.  These are implemented within
.Nm
as separate memory types and can be programmed using data from a file
(see the
.Fl U
option) or from terminal mode (see the
.Ar dump
and
.Ar write
commands).  It is also possible to read the chip (provided it has not
been code-protected previously, of course) and store the data in a
file.  Finally, a ``terminal'' mode is available that allows one to
interactively communicate with the MCU, and to display or program
individual memory cells.
On the STK500 and STK600 programmer, several operational parameters (target supply
voltage, target Aref voltage, programming clock) can be examined and changed
from within terminal mode as well.
.Ss Options
In order to control all the different operation modi, a number of options
need to be specified to
.Nm avrdude .
.Bl -tag -offset indent -width indent
.It Fl p Ar partno
This option specifies the MCU connected to the programmer. The MCU
descriptions are read from the config file. For currently supported MCUs use
? as partno, which will print a list of partno ids and official part names.
Both can be used with the -p option. If -p ? is specified with a specific
programmer, see -c below, then only those parts are output that the
programmer expects to be able to handle, together with the programming
interface(s) that can be used in that combination. In reality there can be
deviations from this list, particularly if programming is directly via a
bootloader.
.Pp
Following parts need special attention:
.Bl -tag -width "ATmega1234"
.It "AT90S1200"
The ISP programming protocol of the AT90S1200 differs in subtle ways
from that of other AVRs.  Thus, not all programmers support this
device.  Known to work are all direct bitbang programmers, and all
programmers talking the STK500v2 protocol.
.It "AT90S2343"
The AT90S2323 and ATtiny22 use the same algorithm.
.It "ATmega2560, ATmega2561"
Flash addressing above 128 KB is not supported by all
programming hardware.  Known to work are jtag2, stk500v2,
and bit-bang programmers.
.It "ATtiny11"
The ATtiny11 can only be
programmed in high-voltage serial mode.
.El
.It Fl p Ar wildcard/flags
Run developer options for MCUs that are matched by wildcard. Whilst
their main use is for developers some flags can be of utility for users, e.g.,
avrdude -p m328p/S outputs AVRDUDE's understanding of ATmega328P MCU properties;
for more information run avrdude -p x/h.
.It Fl b Ar baudrate
Override the RS-232 connection baud rate specified in the respective
programmer's entry of the configuration file.
.It Fl B Ar bitclock
Specify the bit clock period for the JTAG, PDI, TPI, UPDI, or ISP
interface. The value is a floating-point number in microseconds.
Alternatively, the value might be suffixed with "Hz", "kHz" or
"MHz" in order to specify the bit clock frequency rather than a
period. Some programmers default their bit clock value to a 1
microsecond bit clock period, suitable for target MCUs running at 4
MHz clock and above. Slower MCUs need a correspondingly higher bit
clock period. Some programmers reset their bit clock value to the
default value when the programming software signs off, whilst others
store the last used bit clock value. It is recommended to always
specify the bit clock if read/write speed is important.
You can use the 'default_bitclock' keyword in your
.Pa ${HOME}/.config/avrdude/avrdude.rc
or
.Pa ${HOME}/.avrduderc
file to assign a default value to keep from having to specify this
option on every invocation.
.It Fl c Ar programmer-id
Use the programmer specified by the argument.  Programmers and their pin
configurations are read from the config file (see the
.Fl C
option).  New pin configurations can be easily added or modified
through the use of a config file to make
.Nm avrdude
work with different programmers as long as the programmer supports the
Atmel AVR serial program method.  You can use the 'default_programmer'
keyword in your
.Pa ${HOME}/.config/avrdude/avrdude.rc
or
.Pa ${HOME}/.avrduderc
file to assign a default programmer to keep from having to specify
this option on every invocation.
A full list of all supported programmers is output to the terminal 
by using ? as programmer-id.
If -c ? is specified with a specific part, see
-p above, then only those programmers are output that expect
to be able to handle this part, together with the programming interface(s) that can be
used in that combination. In reality there can be deviations from this list,
particularly if programming is directly via a bootloader.
.It Fl c Ar wildcard/flags
Run developer options for programmers that are matched by wildcard. Whilst
their main use is for developers some flags can be of utility for users, e.g.,
avrdude -c usbtiny/S shows AVRDUDE's understanding of usbtiny's properties;
for more information run avrdude -c x/h.
.It Fl C Ar config-file
Use the specified config file to load configuration data.  This file
contains all programmer and part definitions that
.Nm avrdude
knows about.
See the config file, located at
.Pa /etc/avrdude.conf ,
which contains a description of the format.
.Pp
If 
.Ar config-file
is written as
.Pa +filename
then this file is read after the system wide and user configuration
files. This can be used to add entries to the configuration
without patching your system wide configuration file. It can be used
several times, the files are read in same order as given on the command
line.
.It Fl A
Disable the automatic removal of trailing-0xFF sequences in file
input that is to be programmed to flash and in AVR reads from
flash memory. Normally, trailing 0xFFs can be discarded, as flash
programming requires the memory be erased to 0xFF beforehand.
.Fl A
should be used when the programmer hardware, or bootloader
software for that matter, does not carry out chip erase and
instead handles the memory erase on a page level. Popular
Arduino bootloaders exhibit this behaviour; for this reason
.Fl A
is engaged by default when specifying
. Fl c
arduino.
.It Fl D
Disable auto erase for flash.  When the
.Fl U
option with flash memory is specified,
.Nm
will perform a chip erase before starting any of the programming
operations, since it generally is a mistake to program the flash
without performing an erase first.  This option disables that.
Auto erase is not used for ATxmega devices as these devices can
use page erase before writing each page so no explicit chip erase
is required.
Note however that any page not affected by the current operation
will retain its previous contents.
Setting
.Fl D
implies
.Fl A.
.It Fl e
Causes a chip erase to be executed.  This will reset the contents of the
flash ROM and EEPROM to the value
.Ql 0xff ,
and clear all lock bits.
Except for ATxmega devices which can use page erase,
it is basically a prerequisite command before the flash ROM can be
reprogrammed again.  The only exception would be if the new
contents would exclusively cause bits to be programmed from the value
.Ql 1
to
.Ql 0 .
Note that in order to reprogram EEPROM cells, no explicit prior chip
erase is required since the MCU provides an auto-erase cycle in that
case before programming the cell.
.It Xo Fl E Ar exitspec Ns
.Op \&, Ns Ar exitspec
.Xc
By default,
.Nm
leaves the parallel port in the same state at exit as it has been
found at startup.  This option modifies the state of the
.Ql /RESET
and
.Ql Vcc
lines the parallel port is left at, according to the
.Ar exitspec
arguments provided, as follows:
.Bl -tag -width noreset
.It Ar reset
The
.Ql /RESET
signal will be left activated at program exit, that is it will be held
.Em low ,
in order to keep the MCU in reset state afterwards.  Note in particular
that the programming algorithm for the AT90S1200 device mandates that
the
.Ql /RESET
signal is active
.Em before
powering up the MCU, so in case an external power supply is used for this
MCU type, a previous invocation of
.Nm
with this option specified is one of the possible ways to guarantee this
condition.
.Em reset
is supported by the linuxspi and flip2 programmer options, as well as all
parallel port based programmers.
.It Ar noreset
The
.Ql /RESET
line will be deactivated at program exit, thus allowing the MCU target
program to run while the programming hardware remains connected.
.Em noreset
is supported by the linuxspi and flip2 programmer options, as well as all
parallel port based programmers.
.It Ar vcc
This option will leave those parallel port pins active
.Pq \&i. \&e. Em high
that can be used to supply
.Ql Vcc
power to the MCU.
.It Ar novcc
This option will pull the
.Ql Vcc
pins of the parallel port down at program exit.
.It Ar d_high
This option will leave the 8 data pins on the parallel port active.
.Pq \&i. \&e. Em high
.It Ar d_low
This option will leave the 8 data pins on the parallel port inactive.
.Pq \&i. \&e. Em low
.El
.Pp
Multiple
.Ar exitspec
arguments can be separated with commas.
.It Fl F
Normally,
.Nm
tries to verify that the device signature read from the part is
reasonable before continuing.  Since it can happen from time to time
that a device has a broken (erased or overwritten) device signature
but is otherwise operating normally, this options is provided to
override the check.
Also, for programmers like the Atmel STK500 and STK600 which can
adjust parameters local to the programming tool (independent of an
actual connection to a target controller), this option can be used
together with
.Fl t
to continue in terminal mode.
Moreover, the option allows to continue despite failed initialization
of connection between a programmer and a target.
.It Fl i Ar delay
For bitbang-type programmers, delay for approximately
.Ar delay
microseconds between each bit state change.
If the host system is very fast, or the target runs off a slow clock
(like a 32 kHz crystal, or the 128 kHz internal RC oscillator), this
can become necessary to satisfy the requirement that the ISP clock
frequency must not be higher than 1/4 of the CPU clock frequency.
This is implemented as a spin-loop delay to allow even for very
short delays.
On Unix-style operating systems, the spin loop is initially calibrated
against a system timer, so the number of microseconds might be rather
realistic, assuming a constant system load while
.Nm
is running.
On Win32 operating systems, a preconfigured number of cycles per
microsecond is assumed that might be off a bit for very fast or very
slow machines.
.It Fl l Ar logfile
Use
.Ar logfile
rather than
.Va stderr
for diagnostics output.
Note that initial diagnostic messages (during option parsing) are still
written to
.Va stderr
anyway.
.It Fl n
No-write - disables actually writing data to the MCU (useful for debugging
.Nm avrdude
).
.It Fl O
Perform a RC oscillator run-time calibration according to Atmel
application note AVR053.
This is only supported on the STK500v2, AVRISP mkII, and JTAG ICE mkII
hardware.
Note that the result will be stored in the EEPROM cell at address 0.
.It Fl P Ar port
Use
.Ar port
to identify the device to which the programmer is attached.  By
default the
.Pa /dev/ppi0
port is used, but if the programmer type normally connects to the
serial port, the
.Pa /dev/cuaa0
port is the default.  If you need to use a different parallel or
serial port, use this option to specify the alternate port name.
.Pp
On Win32 operating systems, the parallel ports are referred to as lpt1
through lpt3, referring to the addresses 0x378, 0x278, and 0x3BC,
respectively.  If the parallel port can be accessed through a different
address, this address can be specified directly, using the common C
language notation (i. e., hexadecimal values are prefixed by
.Ql 0x
).
.Pp
For the JTAG ICE mkII and JTAGICE3, if
.Nm
has been configured with libusb support,
.Ar port
can alternatively be specified as
.Pa usb Ns Op \&: Ns Ar serialno .
This will cause
.Nm
to search the programmer on USB.
If
.Ar serialno
is also specified, it will be matched against the serial number read
from any JTAG ICE mkII found on USB.
The match is done after stripping any existing colons from the given
serial number, and right-to-left, so only the least significant bytes
from the serial number need to be given.
.Pp
As the AVRISP mkII device can only be talked to over USB, the very
same method of specifying the port is required there.
.Pp
For the USB programmer "AVR-Doper" running in HID mode, the port must
be specified as
.Ar avrdoper.
Libhidapi support is required on Unix and Mac OS but not on Windows. For more
information about AVR-Doper see http://www.obdev.at/avrusb/avrdoper.html.
.Pp
For the USBtinyISP, which is a simplistic device not implementing
serial numbers, multiple devices can be distinguished by their
location in the USB hierarchy.  See the respective
.Em Troubleshooting
entry in the detailed documentation for examples.
.Pp
For the XBee programmer the target MCU is to be programmed wirelessly over a
ZigBee mesh using the XBeeBoot bootloader.  The ZigBee 64-bit address for the
target MCU's own XBee device must be supplied as a 16-character hexadecimal
value as a
.Ar port
prefix, followed by the
.Ql @
character, and the serial device to connect to a second directly contactable
XBee device associated with the same mesh (with a default baud rate of 9600).
This may look similar to:
.Pa 0013a20000000001@/dev/tty.serial .
.Pp
For diagnostic purposes, if the target MCU with an XBeeBoot bootloader is
connected directly to the serial port, the 64-bit address field can be
omitted.  In this mode the default baud rate will be 19200.
.Pp
For programmers that attach to a serial port using some kind of
higher level protocol (as opposed to bit-bang style programmers),
.Ar port
can be specified as
.Pa net Ns \&: Ns Ar host Ns \&: Ns Ar port .
In this case, instead of trying to open a local device, a TCP
network connection to (TCP)
.Ar port
on
.Ar host
is established.
Square brackets may be placed around
.Ar host
to improve readability, for numeric IPv6 addresses (e.g.
.Li net:[2001:db8::42]:1337 ) .
The remote endpoint is assumed to be a terminal or console server
that connects the network stream to a local serial port where the
actual programmer has been attached to.
The port is assumed to be properly configured, for example using a
transparent 8-bit data connection without parity at 115200 Baud
for a STK500.
.Pp
Note: The ability to handle IPv6 hostnames and addresses is limited to
Posix systems (by now).
.It Fl q
Disable (or quell) output of the progress bar while reading or writing
to the device.  Specify it more often for even quieter operations.
.It Fl s, u
These options used to control the obsolete "safemode" feature which
is no longer present. They are silently ignored for backwards compatibility.
.It Fl t
Tells
.Nm
to enter the interactive ``terminal'' mode instead of up- or downloading
files.  See below for a detailed description of the terminal mode.
.It Xo Fl U Ar memtype Ns
.Ar \&: Ns Ar op Ns
.Ar \&: Ns Ar filename Ns
.Op \&: Ns Ar format
.Xc
Perform a memory operation as indicated.  The
.Ar memtype
field specifies the memory type to operate on.
The available memory types are device-dependent, the actual
configuration can be viewed with the
.Cm part
command in terminal mode.
Typically, a device's memory configuration at least contains
the memory types
.Ar flash
and
.Ar eeprom .
All memory types currently known are:
.Bl -tag -width "calibration" -compact
.It calibration
One or more bytes of RC oscillator calibration data.
.It eeprom
The EEPROM of the device.
.It efuse
The extended fuse byte.
.It flash
The flash ROM of the device.
.It fuse
The fuse byte in devices that have only a single fuse byte.
.It hfuse
The high fuse byte.
.It lfuse
The low fuse byte.
.It lock
The lock byte.
.It signature
The three device signature bytes (device ID).
.It fuse Ns Em N
The fuse bytes of ATxmega devices,
.Em N
is an integer number
for each fuse supported by the device.
.It application
The application flash area of ATxmega devices.
.It apptable
The application table flash area of ATxmega devices.
.It boot
The boot flash area of ATxmega devices.
.It prodsig
The production signature (calibration) area of ATxmega devices.
.It usersig
The user signature area of ATxmega devices.
.El
.Pp
The
.Ar op
field specifies what operation to perform:
.Bl -tag -width noreset
.It Ar r
read device memory and write to the specified file
.It Ar w
read data from the specified file and write to the device memory
.It Ar v
read data from both the device and the specified file and perform a verify
.El
.Pp
The
.Ar filename
field indicates the name of the file to read or write.
The
.Ar format
field is optional and contains the format of the file to read or
write.
.Ar Format
can be one of:
.Bl -tag -width sss
.It Ar i
Intel Hex
.It Ar I
Intel Hex with comments on download and tolerance of checksum errors on upload
.It Ar s
Motorola S-record
.It Ar r
raw binary; little-endian byte order, in the case of the flash ROM data
.It Ar e
ELF (Executable and Linkable Format)
.It Ar m
immediate; actual byte values specified on the command line, separated
by commas or spaces.  This is good for programming fuse bytes without
having to create a single-byte file or enter terminal mode.
.It Ar a
auto detect; valid for input only, and only if the input is not
provided at
.Em stdin .
.It Ar d
decimal; this and the following formats are only valid on output.
They generate one line of output for the respective memory section,
forming a comma-separated list of the values.
This can be particularly useful for subsequent processing, like for
fuse bit settings.
.It Ar h
hexadecimal; each value will get the string
.Em 0x
prepended.
Only valid on output.
.It Ar o
octal; each value will get a
.Em 0
prepended unless it is less than 8 in which case it gets no prefix.
Only valid on output.
.It Ar b
binary; each value will get the string
.Em 0b
prepended.
Only valid on output.
.El
.Pp
The default is to use auto detection for input files, and raw binary
format for output files.
Note that if
.Ar filename
contains a colon, the
.Ar format
field is no longer optional since the filename part following the colon
would otherwise be misinterpreted as
.Ar format .
.Pp
When reading any kind of flash memory area (including the various sub-areas
in Xmega devices), the resulting output file will be truncated to not contain
trailing 0xFF bytes which indicate unprogrammed (erased) memory.
Thus, if the entire memory is unprogrammed, this will result in an output
file that has no contents at all.
.Pp
As an abbreviation, the form
.Fl U Ar filename
is equivalent to specifying
.Fl U Em flash:w: Ns Ar filename Ns :a .
This will only work if
.Ar filename
does not have a colon in it.
.It Fl v
Enable verbose output.
More
.Fl v
options increase verbosity level.
.It Fl V
Disable automatic verify check when uploading data.
.It Fl x Ar extended_param
Pass
.Ar extended_param
to the chosen programmer implementation as an extended parameter.
The interpretation of the extended parameter depends on the
programmer itself.
See below for a list of programmers accepting extended parameters.
.El
.Ss Terminal mode
In this mode,
.Nm
only initializes communication with the MCU, and then awaits user
commands on standard input.  Commands and parameters may be
abbreviated to the shortest unambiguous form.  Terminal mode provides
a command history using
.Xr readline 3 ,
so previously entered command lines can be recalled and edited.  The
following commands are currently implemented for all programmers:
.Bl -tag -offset indent -width indent
.It Ar dump  memory addr len
Read
.Ar len
bytes from the specified memory area, and display them in the usual
hexadecimal and ASCII form.
.It Ar dump memory addr ...
Read all bytes from the specified memory starting at address
.Ar addr,
and display them.
.It Ar dump memory addr
Read 256 bytes from the specified memory area, and display them.
.It Ar dump memory ...
Read all bytes from the specified memory, and display them.
.It Ar dump memory
Continue dumping the memory contents for another
.Ar 256
bytes where the previous
.Ar dump
command left off.
.It Ar read
can be used as an alias for dump
.It Ar write memory addr data[,] {data[,]}
Manually program the respective memory cells, starting at address
.Ar addr ,
using the data items provided.
The terminal implements reading from and writing to flash and EEPROM type
memories normally through a cache and paged access functions. All other
memories are directly written to without use of a cache. Some
older parts without paged access will also have flash and EEPROM directly
accessed without cache.
.Pp
.Ar data
can be hexadecimal, octal or decimal integers, floating point numbers
or C-style strings and characters. For integers, an optional case-insensitive
suffix specifies the data size: HH 8 bit, H/S 16 bit, L 32 bit, LL 64 bit.
Suffix D indicates a 64-bit double, F a 32-bit float, whilst a floating point
number without suffix defaults to 32-bit float. Hexadecimal floating point
notation is supported. An ambiguous trailing suffix, e.g., 0x1.8D, is read as
no-suffix float where D is part of the mantissa; use a zero exponent 0x1.8p0D
to clarify.
.Pp
An optional U suffix makes integers unsigned. Ordinary 0x hex integers are
always treated as unsigned. +0x or -0x hex numbers are treated as signed
unless they have a U suffix. Unsigned integers cannot be larger than 2^64-1.
If n is an unsigned integer then -n is also a valid unsigned integer as in C.
Signed integers must fall into the [-2^63, 2^63-1] range or a correspondingly
smaller range when a suffix specifies a smaller type.
.Pp
Ordinary 0x hex integers with n hex digits (counting leading zeros) use the
smallest size of one, two, four and eight bytes that can accommodate any
n-digit hex integer. If an integer suffix specifies a size explicitly the
corresponding number of least significant bytes are written, and a warning
shown if the number does not fit into the desired representation. Otherwise,
unsigned integers occupy the smallest of one, two, four or eight bytes
needed. Signed numbers are allowed to fit into the smallest signed or
smallest unsigned representation: For example, 255 is stored as one byte as
255U would fit in one byte, though as a signed number it would not fit into a
one-byte interval [-128, 127]. The number -1 is stored in one byte whilst -1U
needs eight bytes as it is the same as 0xFFFFffffFFFFffffU.
.Pp
One trailing comma at the end of
.Ar data
items is ignored to facilitate copy & paste of lists.
.It Ar write memory addr len data[,] {data[,]} ...
The ellipsis ... form writes <len> bytes padded by repeating the last
.Ar data
item.
.It Ar flush
Synchronise with the device all pending cached writes to EEPROM or flash.
With some programmer and part combinations, flash (and sometimes EEPROM,
too) looks like a NOR memory, ie, one can only write 0 bits, not 1 bits.
When this is detected, either page erase is deployed (e.g., with parts that
have PDI/UPDI interfaces), or if that is not available, both EEPROM and
flash caches are fully read in, a chip erase command is issued and both
EEPROM and flash are written back to the device. Hence, it can take
minutes to ensure that a single previously cleared bit is set and,
therefore, this command should be used sparingly.
.It Ar abort
Normally, caches are only ever
actually written to the device when using the
.Ar flush
command, at the end of the terminal session after typing
.Ar quit ,
or after EOF on input is encountered. The abort command resets
the cache discarding all previous writes to the flash and EEPROM cache.
.It Ar erase
Perform a chip erase and discard all pending writes to EEPROM and flash.
.It Ar sig
Display the device signature bytes.
.It Ar part
Display the current part settings and parameters.  Includes chip
specific information including all memory types supported by the
device, read/write timing, etc.
.It Ar verbose Op Ar level
Change (when
.Ar level
is provided), or display the verbosity level.
The initial verbosity level is controlled by the number of
.Fl v
options given on the commandline.
.It Ar quell Op Ar level
Change (when
.Ar level
is provided), or display the quell level. 1 is used to suppress progress reports.
2 or higher yields in progressively quieter operations.
The initial quell level is controlled by the number of
.Fl q
options given on the commandline.
.It Ar \&?
.It Ar help
Give a short on-line summary of the available commands.
.It Ar quit
Leave terminal mode and thus
.Nm avrdude .
.El
.Pp
The terminal commands below may only be implemented on some specific programmers, and may therefore not be available in the help menu.
.Bl -tag -offset indent -width indent
.It pgerase memory addr
Erase one page of the memory specified.
.It Ar send b1 b2 b3 b4
Send raw instruction codes to the AVR device.  If you need access to a
feature of an AVR part that is not directly supported by
.Nm ,
this command allows you to use it, even though
.Nm
does not implement the command. When using direct SPI mode, up to 3 bytes
can be omitted.
.It Ar spi
Enter direct SPI mode.  The
.Em pgmled
pin acts as chip select.
.Em Supported on parallel bitbang programmers, and partially by USBtiny.
.It Ar pgm
Return to programming mode (from direct SPI mode).
.It Ar vtarg voltage
Set the target's supply voltage to
.Ar voltage
Volts.
.Em Supported on the STK500 and STK600 programmer.
.It Ar varef Oo Ar channel Oc Ar voltage
Set the adjustable voltage source to
.Ar voltage
Volts.
This voltage is normally used to drive the target's
.Em Aref
input on the STK500.
On the Atmel STK600, two reference voltages are available, which
can be selected by the optional
.Ar channel
argument (either 0 or 1).
.Em Supported on the STK500 and STK600 programmer.
.It Ar fosc freq Ns Op M Ns \&| Ns k
Set the programming oscillator to
.Ar freq
Hz.
An optional trailing letter
.Ar \&M
multiplies by 1E6, a trailing letter
.Ar \&k
by 1E3.
.Em Supported on the STK500 and STK600 programmer.
.It Ar fosc off
Turn the programming oscillator off.
.Em Supported on the STK500 and STK600 programmer.
.It Ar sck period
.Em STK500 and STK600 programmer:
Set the SCK clock period to
.Ar period
microseconds.
.Em JTAG ICE:
Set the JTAG ICE bit clock period to
.Ar period
microseconds.
Note that unlike STK500 settings, this setting will be reverted to
its default value (approximately 1 microsecond) when the programming
software signs off from the JTAG ICE.
This parameter can also be used on the JTAG ICE mkII, JTAGICE3, and Atmel-ICE to specify the
ISP clock period when operating the ICE in ISP mode.
.It Ar parms
.Em STK500 and STK600 programmer:
Display the current voltage and programming oscillator parameters.
.Em JTAG ICE:
Display the current target supply voltage and JTAG bit clock rate/period.
.Em Other programmers:
Display the programmer specific parameters.
.El
.Ss Default Parallel port pin connections
(these can be changed, see the
.Fl c
option)
.TS
ll.
\fBPin number\fP	\fBFunction\fP
2-5	Vcc (optional power supply to MCU)
7	/RESET (to MCU)
8	SCK (to MCU)
9	SDO (to MCU)
10	SDI (from MCU)
18-25	GND
.TE
.Ss debugWire limitations
The debugWire protocol is Atmel's proprietary one-wire (plus ground)
protocol to allow an in-circuit emulation of the smaller AVR devices,
using the
.Ql /RESET
line.
DebugWire mode is initiated by activating the
.Ql DWEN
fuse, and then power-cycling the target.
While this mode is mainly intended for debugging/emulation, it
also offers limited programming capabilities.
Effectively, the only memory areas that can be read or programmed
in this mode are flash ROM and EEPROM.
It is also possible to read out the signature.
All other memory areas cannot be accessed.
There is no
.Em chip erase
functionality in debugWire mode; instead, while reprogramming the
flash ROM, each flash ROM page is erased right before updating it.
This is done transparently by the JTAG ICE mkII (or AVR Dragon).
The only way back from debugWire mode is to initiate a special
sequence of commands to the JTAG ICE mkII (or AVR Dragon), so the
debugWire mode will be temporarily disabled, and the target can
be accessed using normal ISP programming.
This sequence is automatically initiated by using the JTAG ICE mkII
or AVR Dragon in ISP mode, when they detect that ISP mode cannot be
entered.
.Ss FLIP version 1 idiosyncrasies
Bootloaders using the FLIP protocol version 1 experience some very
specific behaviour.
.Pp
These bootloaders have no option to access memory areas other than
Flash and EEPROM.
.Pp
When the bootloader is started, it enters a
.Em security mode
where the only acceptable access is to query the device configuration
parameters (which are used for the signature on AVR devices).
The only way to leave this mode is a
.Em chip erase .
As a chip erase is normally implied by the
.Fl U
option when reprogramming the flash, this peculiarity might not be
very obvious immediately.
.Pp
Sometimes, a bootloader with security mode already disabled seems to
no longer respond with sensible configuration data, but only 0xFF for
all queries.
As these queries are used to obtain the equivalent of a signature,
.Nm
can only continue in that situation by forcing the signature check
to be overridden with the
.Fl F
option.
.Pp
A
.Em chip erase
might leave the EEPROM unerased, at least on some
versions of the bootloader.
.Ss Programmers accepting extended parameters
.Bl -tag -offset indent -width indent
.It Ar JTAG ICE mkII
.It Ar JTAGICE3
.It Ar Atmel-ICE
.It Ar Power Debugger
.It Ar PICkit 4
.It Ar MPLAB SNAP
.It Ar AVR Dragon
When using the JTAG ICE mkII, JTAGICE3, Atmel-ICE, PICkit 4, MPLAB SNAP,
Power Debugger or AVR Dragon in JTAG mode, the following extended parameter
is accepted:
.Bl -tag -offset indent -width indent
.It Ar jtagchain=UB,UA,BB,BA
Setup the JTAG scan chain for
.Ar UB
units before,
.Ar UA
units after,
.Ar BB
bits before, and
.Ar BA
bits after the target AVR, respectively.
Each AVR unit within the chain shifts by 4 bits.
Other JTAG units might require a different bit shift count.
.El
.Pp
The PICkit 4 and the Power Debugger also supports high-voltage UPDI programming.
This is used to enable a UPDI pin that has previously been set to RESET or
GPIO mode. High-voltage UPDI can be utilized by using an extended parameter:
.Bl -tag -offset indent -width indent
.It Ar hvupdi
Enable high-voltage UPDI initialization for targets that supports this.
.El
.It Ar AVR910
.Bl -tag -offset indent -width indent
.It Ar devcode=VALUE
Override the device code selection by using
.Ar VALUE
as the device code.
The programmer is not queried for the list of supported
device codes, and the specified
.Ar VALUE
is not verified but used directly within the
.Ql T
command sent to the programmer.
.Ar VALUE
can be specified using the conventional number notation of the
C programming language.
.El
.Bl -tag -offset indent -width indent
.It Ar no_blockmode
Disables the default checking for block transfer capability.
Use 
.Ar no_blockmode
only if your
.Ar AVR910
programmer creates errors during initial sequence. 
.El
.It Ar Arduino
.Bl -tag -offset indent -width indent
.It Ar attemps[=<1..99>]
Specify how many connection retry attemps to perform before exiting.
Defaults to 10 if not specified.
.El
.It Ar Urclock
.Bl -tag -offset indent -width indent
.It Ar showall
Show all info for the connected part, then exit. The -xshow... options
below can be used to assemble a bespoke response consisting of a subset
(or only one item) of all available relevant information about the
connected part and bootloader.
.It Ar showid
Show a unique Urclock ID stored in either flash or EEPROM of the MCU, then exit.
.It Ar id=<E|F>.<addr>.<len>
Historically, the Urclock ID was a six-byte unique little-endian number
stored in Urclock boards at EEPROM address 257. The location of this
number can be set by the -xid=<E|F>.<addr>.<len> extended parameter. E
stands for EEPROM and F stands for flash. A negative address addr counts
from the end of EEPROM and flash, respectively. The length len of the
Urclock ID can be between 1 and 8 bytes.
.It Ar showdate
Show the last-modified date of the input file for the flash application,
then exit. If the input file was stdin, the date will be that of the
programming.  Date and filename are part of the metadata that the urclock
programmer stores by default in high flash just under the bootloader; see also
-xnometadata.
.It Ar showfilename
Show the input filename (or title) of the last flash writing session, then exit.
.It Ar title=<string>
When set, <string> will be used in lieu of the input filename. The maximum
string length for the title/filename field is 254 bytes including
terminating nul.
.It Ar showapp
Show the size of the programmed application, then exit.
.It Ar showstore
Show the size of the unused flash between the application and metadata, then exit.
.It Ar showmeta
Show the size of the metadata just below the bootloader, then exit.
.It Ar showboot
Show the size of the bootloader, then exit.
.It Ar showversion
Show bootloader version and capabilities, then exit.
.It Ar showvector
Show the vector number and name of the interrupt table vector used by the
bootloader for starting the application, then exit. For hardware-supported
bootloaders this will be vector 0 (Reset), and for vector bootloaders this
will be any other vector number of the interrupt vector table or the slot
just behind the vector table with the name VBL_ADDITIONAL_VECTOR.
.It Ar showpart
Show the part for which the bootloader was compiled, then exit.
.It Ar bootsize=<size>
Manual override for bootloader size. Urboot bootloaders put the number of
used bootloader pages into a table at the top of the bootloader section,
ie, typically top of flash, so the urclock programmer can look up the
bootloader size itself. In backward-compatibility mode, when programming
via other bootloaders, this option can be used to tell the programmer the
size, and therefore the location, of the bootloader.
.It Ar vectornum=<arg>
Manual override for vector number. Urboot bootloaders put the vector
number used by a vector bootloader into a table at the top of flash, so
this option is normally not needed for urboot bootloaders. However, it is
useful in backward-compatibility mode (or when the urboot bootloader does
not offer flash read). Specifying a vector number in these circumstances
implies a vector bootloader whilst the default assumption would be a
hardware-supported bootloader.
.It Ar eepromrw
Manual override for asserting EEPROM read/write capability. Not normally
needed for urboot bootloaders, but useful for in backward-compatibility
mode if the bootloader offers EEPROM read/write.
.It Ar emulate_ce
If an urboot bootloader does not offer a chip erase command it will tell
the urclock programmer so during handshake. In this case the urclock
programmer emulates a chip erase, if warranted by user command line
options, by filling the remainder of unused flash below the bootloader
with 0xff. If this option is specified, the urclock programmer will assume
that the bootloader cannot erase the chip itself. The option is useful
for backwards-compatible bootloaders that do not implement chip erase.
.It Ar restore
Upload unchanged flash input files and trim below the bootloader if
needed. This is most useful when one has a backup of the full flash and
wants to play that back onto the device. No metadata are written in this
case and no vector patching happens either if it is a vector bootloader.
However, for vector bootloaders, even under the option -xrestore an
input file will not be uploaded for which the reset vector does not point
to the vector bootloader. This is to avoid writing an input file to the
device that would render the vector bootloader not functional as it would
not be reached after reset.
.It Ar initstore
On writing to flash fill the store space between the flash application and
the metadata section with 0xff.
.It Ar nofilename
On writing to flash do not store the application input filename (nor a title).
.It Ar nodate
On writing to flash do not store the application input filename (nor a
title) and no date either.
.It Ar nometadata
On writing to flash do not store any metadata. The full flash below the
bootloader is available for the application. In particular, no data store
frame is programmed.
.It Ar delay=<n>
Add a <n> ms delay after reset. This can be useful if a board takes a
particularly long time to exit from external reset. <n> can be negative,
in which case the default 120 ms delay after issuing reset will be
shortened accordingly.
.It Ar strict
Urclock has a faster, but slightly different strategy than -c arduino to
synchronise with the bootloader; some stk500v1 bootloaders cannot cope
with this, and they need the -xstrict option.
.It Ar help
Show this help menu and exit
.El
.It Ar buspirate
.Bl -tag -offset indent -width indent
.It Ar reset={cs,aux,aux2}
The default setup assumes the BusPirate's CS output pin connected to 
the RESET pin on AVR side. It is however possible to have multiple AVRs
connected to the same BP with SDI, SDO and SCK lines common for all of them.
In such a case one AVR should have its RESET connected to BusPirate's
.Pa CS
pin, second AVR's RESET connected to BusPirate's
.Pa AUX
pin and if your BusPirate has an
.Pa AUX2
pin (only available on BusPirate version v1a with firmware 3.0 or newer)
use that to activate RESET on the third AVR.
.Pp
It may be a good idea to decouple the BusPirate and the AVR's SPI buses from 
each other using a 3-state bus buffer. For example 74HC125 or 74HC244 are some
good candidates with the latches driven by the appropriate reset pin (cs, 
aux or aux2). Otherwise the SPI traffic in one active circuit may interfere
with programming the AVR in the other design.
.It Ar spifreq=<0..7>
The SPI speed for the Bus Pirate's binary SPI mode:
.Bd -literal
0 ..  30 kHz   (default)
1 .. 125 kHz
2 .. 250 kHz
3 ..   1 MHz
4 ..   2 MHz
5 ..   2.6 MHz
6 ..   4 MHz
7 ..   8 MHz
.Ed
.It Ar rawfreq=<0..3>
Sets the SPI speed and uses the Bus Pirate's binary "raw-wire" mode:
.Bd -literal
0 ..   5 kHz
1 ..  50 kHz
2 .. 100 kHz   (Firmware v4.2+ only)
3 .. 400 kHz   (v4.2+)
.Ed
.Pp
The only advantage of the "raw-wire" mode is the different SPI frequencies
available. Paged writing is not implemented in this mode.
.It Ar ascii
Attempt to use ASCII mode even when the firmware supports BinMode (binary
mode). 
BinMode is supported in firmware 2.7 and newer, older FW's either don't
have BinMode or their BinMode is buggy. ASCII mode is slower and makes 
the above
.Ar reset= , spifreq=
and 
.Ar rawfreq=
parameters unavailable. Be aware that ASCII mode is not guaranteed to work
with newer firmware versions, and is retained only to maintain compatibility
with older firmware versions.
.It Ar nopagedwrite
Firmware versions 5.10 and newer support a binary mode SPI command that enables
whole pages to be written to AVR flash memory at once, resulting in a
significant write speed increase. If use of this mode is not desirable for some
reason, this option disables it.
.It Ar nopagedread
Newer firmware versions support in binary mode SPI command some AVR Extended 
Commands. Using the "Bulk Memory Read from Flash" results in a
significant read speed increase. If use of this mode is not desirable for some
reason, this option disables it.
.It Ar cpufreq=<125..4000>
This sets the AUX pin to output a frequency of 
.Ar n
kHz. Connecting
the AUX pin to the XTAL1 pin of your MCU, you can provide it a clock, 
for example when it needs an external clock because of wrong fuses settings.
Make sure the CPU frequency is at least four times the SPI frequency.  
.It Ar serial_recv_timeout=<1...>
This sets the serial receive timeout to the given value. 
The timeout happens every time avrdude waits for the BusPirate prompt. 
Especially in ascii mode this happens very often, so setting a smaller value 
can speed up programming a lot. 
The default value is 100ms. Using 10ms might work in most cases. 
.El
.It Ar Micronucleus bootloader
.Bl -tag -offset indent -width indent
.It Ar wait[=<timeout>]
If the device is not connected, wait for the device to be plugged in.
The optional
.Ar timeout
specifies the connection time-out in seconds.
If no time-out is specified, AVRDUDE will wait indefinitely until the
device is plugged in.
.El
.It Ar Teensy bootloader
.Bl -tag -offset indent -width indent
.It Ar wait[=<timeout>]
If the device is not connected, wait for the device to be plugged in.
The optional
.Ar timeout
specifies the connection time-out in seconds.
If no time-out is specified, AVRDUDE will wait indefinitely until the
device is plugged in.
.El
.It Ar Wiring
When using the Wiring programmer type, the
following optional extended parameter is accepted:
.Bl -tag -offset indent -width indent
.It Ar snooze=<0..32767>
After performing the port open phase, AVRDUDE will wait/snooze for
.Ar snooze
milliseconds before continuing to the protocol sync phase.
No toggling of DTR/RTS is performed if
.Ar snooze
is greater than 0.
.El
.It Ar PICkit2
Connection to the PICkit2 programmer:
.Bd -literal
(AVR)    (PICkit2)
RST  -   VPP/MCLR (1) 
VDD  -   VDD Target (2) -- possibly optional if AVR self powered 
GND  -   GND (3) 
SDI  -   PGD (4)
SCLK -   PDC (5) 
SDO  -   AUX (6)

.Ed
Extended commandline parameters:
.Bl -tag -offset indent -width indent
.It Ar clockrate=<rate>
Sets the SPI clocking rate in Hz (default is 100kHz). Alternately the -B or -i options can be used to set the period.
.It Ar timeout=<usb-transaction-timeout>
Sets the timeout for USB reads and writes in milliseconds (default is 1500 ms).
.El
.It Ar USBasp
Extended parameters:
.Bl -tag -offset indent -width indent
.It Ar section_config
Programmer will erase configuration section with option
.Fl e
(chip erase), rather than entire chip.
Only applicable to TPI devices (ATtiny 4/5/9/10/20/40).
.El
.It Ar xbee
Extended parameters:
.Bl -tag -offset indent -width indent
.It Ar xbeeresetpin=<1..7>
Select the XBee pin DIO<1..7> that is connected to the MCU's
.Ql /RESET
line.  The programmer needs to know which DIO pin to use to reset into the
bootloader.  The default (3) is the DIO3 pin (XBee pin 17), but some
commercial products use a different XBee pin.
.Pp
The remaining two necessary XBee-to-MCU connections are not selectable - the
XBee DOUT pin (pin 2) must be connected to the MCU's
.Ql RXD
line, and the XBee DIN pin (pin 3) must be connected to the MCU's
.Ql TXD
line.
.El
.It Ar STK500
.Bl -tag -offset indent -width indent
.It Ar attemps[=<1..99>]
Specify how many connection retry attemps to perform before exiting.
Defaults to 10 if not specified.
.El
.It Ar serialupdi
Extended parameters:
.Bl -tag -offset indent -width indent
.It Ar rtsdtr=low|high
Forces RTS/DTR lines to assume low or high state during the whole
programming session. Some programmers might use this signal to
indicate UPDI programming state, but this is strictly hardware
specific.
.Pp
When not provided, driver/OS default value will be used.
.El
.It Ar linuxspi
Extended parameter:
.Bl -tag -offset indent -width indent
.It Ar disable_no_cs
Ensures the programmer does not use the SPI_NO_CS bit for the SPI
driver. This parameter is useful for kernels that do not support
the CS line being managed outside the application.
.El
.El
.Sh FILES
.Bl -tag -offset indent -width /dev/ppi0XXX
.It Pa /dev/ppi0
Default device to be used for communication with the programming
hardware
.It Pa avrdude.conf
Programmer and parts configuration file
.Pp
On Windows systems, this file is looked up in the same directory as the
executable file.
On all other systems, the file is first looked up in
.Pa ../etc/ ,
relative to the path of the executable, then in the same directory as
the executable itself, and finally in the system default location
.Pa /etc/avrdude.conf .
.It Pa ${XDG_CONFIG_HOME}/avrdude/avrdude.rc
Local programmer and parts configuration file (per-user overrides); it follows the same syntax as
.Pa avrdude.conf ;
if the
.Pa ${XDG_CONFIG_HOME}
environment variable is not set or empty, the directory
.Pa ${HOME}/.config/
is used instead.
.It Pa ${HOME}/.avrduderc
Alternative location of the per-user configuration file if above file does not exist
.It Pa ~/.inputrc
Initialization file for the
.Xr readline 3
library
.It Pa /usr/share/doc/avrdude/avrdude.pdf.gz
User manual
.El
.\" .Sh EXAMPLES
.Sh DIAGNOSTICS
.Bd -literal
avrdude: jtagmkII_setparm(): bad response to set parameter command: RSP_FAILED
avrdude: jtagmkII_getsync(): ISP activation failed, trying debugWire
avrdude: Target prepared for ISP, signed off.
avrdude: Please restart avrdude without power-cycling the target.
.Ed
.Pp
If the target AVR has been set up for debugWire mode (i. e. the
.Em DWEN
fuse is programmed), normal ISP connection attempts will fail as
the
.Em /RESET
pin is not available.
When using the JTAG ICE mkII in ISP mode, the message shown indicates
that
.Nm
has guessed this condition, and tried to initiate a debugWire reset
to the target.
When successful, this will leave the target AVR in a state where it
can respond to normal ISP communication again (until the next power
cycle).
Typically, the same command is going to be retried again immediately
afterwards, and will then succeed connecting to the target using
normal ISP communication.
.Sh SEE ALSO
.Xr avr-objcopy 1 ,
.Xr ppi 4 ,
.Xr libelf 3,
.Xr readline 3
.Pp
The AVR microcontroller product description can be found at
.Pp
.Dl "http://www.atmel.com/products/AVR/"
.\" .Sh HISTORY
.Sh AUTHORS
.Nm Avrdude
was written by Brian S. Dean <bsd@bsdhome.com>.
.Pp
This man page by
.ie t J\(:org Wunsch.
.el Joerg Wunsch.
.Sh BUGS
Please report bugs via
.Dl "https://github.com/avrdudes/avrdude/issues"
.Pp
The JTAG ICE programmers currently cannot write to the flash ROM
one byte at a time.
For that reason, updating the flash ROM from terminal mode does not
work.
.Pp
Page-mode programming the EEPROM through JTAG (i.e. through an
.Fl U
option) requires a prior chip erase.
This is an inherent feature of the way JTAG EEPROM programming works.
This also applies to the STK500 and STK600 in parallel programming mode.
.Pp
The USBasp and USBtinyISP drivers do not offer any option to distinguish multiple
devices connected simultaneously, so effectively only a single device
is supported.
.Pp
Chip Select must be externally held low for direct SPI when
using USBtinyISP, and send must be a multiple of four bytes.
.Pp
The avrftdi driver allows one to select specific devices using any combination of vid,pid
serial number (usbsn) vendor description (usbvendoror part description (usbproduct)
as seen with lsusb or whatever tool used to view USB device information. Multiple 
devices can be on the bus at the same time. For the H parts, which have multiple MPSSE
interfaces, the interface can also be selected.  It defaults to interface 'A'.