'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Device manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\" $Id$
'\"
.TH DS2720 3  2003 "OWFS Manpage" "One-Wire File System"
.SH NAME
.B DS2720
\- Efficient Addressable Single-cell Rechargeable Lithium Protection IC
.SH SYNOPSIS
Memory and warnings.
.PP
.B 31
[.]XXXXXXXXXXXX[XX][/[
.B lock.[0-1|ALL]
|
.B memory
|
.B pages/page.[0-1|ALL]
|
.br
.B cc
|
.B ce
|
.B dc
|
.B de
|
.B doc
|
.B ot
|
.B ov
|
.B psf
|
.B uv
|
.br
'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Program manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\" $Id$
'\"
.B address
|
.B crc8
|
.B id
|
.B locator
|
.B r_address
|
.B r_id
|
.B r_locator
|
.B type
]]
.SH FAMILY CODE
.PP
.I 31
.SH SPECIAL PROPERTIES
.SS lock.[0-1|ALL]
.I read-write, yes-no
.br
Lock either of the two eprom pages to prevent further writes. Apparently setting
.I lock
is permanent.
.SS memory
.I read-write, binary
.br
Access to the full 256 byte memory range. Much of this space is reserved or special use. User space is the
.I page
area.
.br
See the
.I DATASHEET
for a full memory map.
.SS pages/pages.[0-1|ALL]
.I read-write, binary
Two 8 byte areas of memory for user application. The
.I lock
property can prevent further alteration.
.br
NOTE that the
.I page
property is different from the common 
.I OWFS
implementation in that all of
.I memory
is not accessible.
.SH OBSCURE PROPERTIES
.SS cc ce dc de doc ot ov uv
.I varies, yes-no
.br
Bit flags corresponding to various battery management functions of the chip. See the 
.I DATASHEET
for details of the identically named entries.
.br
In general, writing "0" corresponds to a 0 bit value, and non-zero corresponds to a 1 bit value.
.SH STANDARD PROPERTIES
'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Program manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\" $Id$
'\"
.SS address
.SS r_address
.I read-only, ascii
.br
The entire 64-bit unique ID. Given as upper case hexadecimal digits (0-9A-F).
.br
.I address
starts with the
.I family
code
.br
.I r address
is the
.I address
in reverse order, which is often used in other applications and labeling.
.SS crc8
.I read-only, ascii
.br
The 8-bit error correction portion. Uses cyclic redundancy check. Computed from the preceding 56 bits of the unique ID number. Given as upper case hexadecimal digits (0-9A-F).
.SS family
.I read-only, ascii
.br
The 8-bit family code. Unique to each
.I type
of device. Given as upper case hexadecimal digits (0-9A-F).
.SS id
.SS r_id
.I read-only, ascii
.br
The 48-bit middle portion of the unique ID number. Does not include the family code or CRC. Given as upper case hexadecimal digits (0-9A-F).
.br
.I r id
is the
.I id
in reverse order, which is often used in other applications and labeling.
.SS locator
.SS r_locator
.I read-only, ascii
.br
Uses an extension of the 1-wire design from iButtonLink company that associated 1-wire physical connections with a unique 1-wire code. If the connection is behind a
.B Link Locator
the
.I locator will show a unique 8-byte number (16 character hexadecimal) starting with family code FE.
.br
If no
.B Link Locator
is between the device and the master, the
.I locator
field will be all FF.
.br
.I r locator
is the
.I locator
in reverse order.
.SS present (DEPRECATED)
.I read-only, yes-no
.br
Is the device currently
.I present
on the 1-wire bus?
.SS type
.I read-only, ascii
.br
Part name assigned by Dallas Semi. E.g.
.I DS2401
Alternative packaging (iButton vs chip) will not be distiguished.
.SH ALARMS
None.
.SH DESCRIPTION
'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Program manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\" $Id$
'\"
.SS 1-Wire
.I 1-wire 
is a wiring protocol and series of devices designed and manufactured
by Dallas Semiconductor, Inc. The bus is a low-power low-speed low-connector
scheme where the data line can also provide power.
.PP
Each device is uniquely and unalterably numbered during manufacture. There are a wide variety
of devices, including memory, sensors (humidity, temperature, voltage,
contact, current), switches, timers and data loggers. More complex devices (like
thermocouple sensors) can be built with these basic devices. There are also
1-wire devices that have encryption included.
.PP
The 1-wire scheme uses a single 
.I bus master
and multiple
.I slaves
on the same wire. The bus master initiates all communication. The slaves can be 
individually discovered and addressed using their unique ID.
.PP
Bus masters come in a variety of configurations including serial, parallel, i2c, network or USB
adapters.
.SS OWFS design
.I OWFS
is a suite of programs that designed to make the 1-wire bus and its
devices easily accessible. The underlying principle is to create a virtual
filesystem, with the unique ID being the directory, and the individual
properties of the device are represented as simple files that can be read and written.
.PP 
Details of the individual slave or master design are hidden behind a consistent interface. The goal is to 
provide an easy set of tools for a software designer to create monitoring or control applications. There 
are some performance enhancements in the implementation, including data caching, parallel access to bus 
masters, and aggregation of device communication. Still the fundemental goal has been ease of use, flexibility 
and correctness rather than speed.
.SS DS2720
The
.B DS2720 (3)
is a battery charging monitor. Besides it's intended use, it may have use in monitoring for device failures.
.SH ADDRESSING
'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Program manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\" $Id$
'\"
All 1-wire devices are factory assigned a unique 64-bit address. This address is of the form:
.TP
.B Family Code
8 bits
.TP
.B Address
48 bits
.TP
.B CRC
8 bits
.IP
.PP
Addressing under OWFS is in hexadecimal, of form:
.IP
.B 01.123456789ABC
.PP
where
.B 01
is an example 8-bit family code, and
.B 12345678ABC
is an example 48 bit address.
.PP
The dot is optional, and the CRC code can included. If included, it must be correct.
.SH DATASHEET
.br
http://pdfserv.maxim-ic.com/en/ds/DS2720.pdf
.SH SEE ALSO
.SS Programs
.B owfs (1) owhttpd (1) owftpd (1) owserver (1)
.B owdir (1) owread (1) owwrite (1) owpresent (1)
.B owtap (1)
.SS Configuration and testing
.B owfs (5) owtap (1) owmon (1)
.SS Language bindings
.B owtcl (3) owperl (3) owcapi (3)
.SS Clocks
.B DS1427 (3) DS1904 (3) DS1994 (3) DS2404 (3) DS2404S (3) DS2415 (3) DS2417 (3)
.SS ID
.B DS2401 (3) DS2411 (3) DS1990A (3)
.SS Memory
.B DS1982 (3) DS1985 (3) DS1986 (3) DS1991 (3) DS1992 (3) DS1993 (3) DS1995 (3) DS1996 (3) DS2430A (3) DS2431 (3) DS2433 (3) DS2502 (3) DS2506 (3) DS28E04 (3) DS28EC20 (3)
.SS Switches
.B DS2405 (3) DS2406 (3) DS2408 (3) DS2409 (3) DS2413 (3) DS28EA00 (3)
.SS Temperature
.B DS1822 (3) DS1825 (3) DS1820 (3) DS18B20 (3) DS18S20 (3) DS1920 (3) DS1921 (3) DS1821 (3) DS28EA00 (3) DS28E04 (3) EDS0064 (3) EDS0065 (3) EDS0066 (3) EDS0067 (3) EDS0068 (3) EDS0071 (3) EDS0072 (3) MAX31826 (3)
.SS Humidity
.B DS1922 (3) DS2438 (3) EDS0065 (3) EDS0068 (3)
.SS Voltage
.B DS2450 (3)
.SS Resistance
.B DS2890 (3)
.SS Multifunction (current, voltage, temperature)
.B DS2436 (3) DS2437 (3) DS2438 (3) DS2751 (3) DS2755 (3) DS2756 (3) DS2760 (3) DS2770 (3) DS2780 (3) DS2781 (3) DS2788 (3) DS2784 (3)
.SS Counter
.B DS2423 (3)
.SS LCD Screen
.B LCD (3) DS2408 (3)
.SS Crypto
.B DS1977 (3)
.SS Pressure
.B DS2406 (3) TAI8570 (3) EDS0066 (3) EDS0068 (3)
.SS Moisture
.B EEEF (3) DS2438 (3)
.SH AVAILABILITY
http://www.owfs.org
.SH AUTHOR
Paul Alfille (paul.alfille@gmail.com)