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DS28E04-100(3)		     One-Wire File System		DS28E04-100(3)

NAME
       DS28E04 - 1-Wire	EEPROM chip (4096-bit) with seven address inputs

SYNOPSIS
       4096-bit	EEPROM,	2 port switch

       1C  [.]XXXXXXXXXXXX[XX][/[  latch.[0-1|ALL|BYTE]	| PIO.[0-1|ALL|BYTE] |
       power | sensed.[0-1|ALL|BYTE] | polarity	| por |	set_alarm | address  |
       crc8 | id | locator | r_address | r_id |	r_locator | type ]]

FAMILY CODE
       1C

SPECIAL	PROPERTIES
   latch.0 latch.1 latch.ALL latch.BYTE
       read-write, binary
       The  2  pins  (PIO) latch a bit when their state	changes, either	exter-
       nally, or through a write to the	pin.
       Reading the latch property indicates that the latch has been set.
       Writing any data	to ANY latch will reset	them all. (This	is  the	 hard-
       ware design).
       ALL is all latch	states,	accessed simultaneously, comma separated.
       BYTE references all channels simultaneously as a	single byte. Channel 0
       is bit 0.

   PIO.0 PIO.1 PIO.ALL PIO.BYTE
       read-write, yes-no
       State of	the open-drain output (	PIO ) pin. 0 = non-conducting =	off, 1
       = conducting = on.
       Writing	zero  will  turn  off  the  switch,  non-zero will turn	on the
       switch. Reading the PIO state will return the switch setting. To	deter-
       mine  the  actual  logic	 level	at  the	 switch, refer to the sensed.0
       sensed.1	sensed.ALL sensed.BYTE property.
       ALL references all channels simultaneously, comma separated.
       BYTE references all channels simultaneously as a	single byte. Channel 0
       is bit 0.

   power
       read-only, yes-no
       Is  the DS28E04 powered parasitically (=0) or separately	on the Vcc pin
       (=1)?

   sensed.0 sensed.1 sensed.ALL	sensed.BYTE
       read-only, yes-no
       Logic level at the PIO pin. 0 = ground. 1 = high	(~2.4V - 5V ).	Really
       makes  sense only if the	PIO state is set to zero (off),	else will read
       zero.
       ALL references all channels simultaneously, comma separated.
       BYTE references all channels simultaneously as a	single byte. Channel 0
       is bit 0.

   polarity
       read-only, yes-no
       Reports	the  state  of the POL pin. The	state of the POL pin specifies
       whether the PIO pins P0 and P1 power up high or low. The	polarity of  a
       pulse  generated	 at  a	PIO  pin is the	opposite of the	pin's power-up
       state.

       0      PIO powers up 0

       1      PIO powers up 1

   por
       read-write, yes-no
       Specifies whether the device has	performed power-on reset. This bit can
       only  be	 cleared to 0 under software control. As long as this bit is 1
       the device will allways respond to a conditional	search.

   set_alarm
       read-write, integer unsigned (0-333)
       A number	consisting of 3	digits XYY, where:

       X      select source and	logical	term
	      0	PIO   OR
	      1	latch OR
	      2	PIO   AND
	      3	latch AND

       Y      select channel and polarity
	      0	Unselected (LOW)
	      1	Unselected (HIGH)
	      2	Selected    LOW
	      3	Selected    HIGH

       All digits will be truncated to the 0-3 range. Leading zeroes  are  op-
       tional. Low-order digit is channel 0.

       Example:

       133    Responds	on  Conditional	Search when latch.1 or latch.0 are set
	      to 1.

       222    Responds on Conditional Search when sensed.1  and	 sensed.0  are
	      set to 0.

       000 (0)
	      Never responds to	Conditional Search.

STANDARD PROPERTIES
   address
   r_address
       read-only, ascii
       The  entire  64-bit  unique  ID.	Given as upper case hexidecimal	digits
       (0-9A-F).
       address starts with the family code
       r address is the	address	in reverse order, which	is often used in other
       applications and	labeling.

   crc8
       read-only, ascii
       The  8-bit error	correction portion. Uses cyclic	redundancy check. Com-
       puted from the preceding	56 bits	of the unique ID number. Given as  up-
       per case	hexidecimal digits (0-9A-F).

   family
       read-only, ascii
       The  8-bit  family  code. Unique	to each	type of	device.	Given as upper
       case hexidecimal	digits (0-9A-F).

   id
   r_id
       read-only, ascii
       The 48-bit middle portion of the	unique ID number. Does not include the
       family code or CRC. Given as upper case hexidecimal digits (0-9A-F).
       r  id is	the id in reverse order, which is often	used in	other applica-
       tions and labeling.

   locator
   r_locator
       read-only, ascii
       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 Link Locator the locator will	show a	unique
       8-byte number (16 character hexidecimal)	starting with family code FE.
       If  no  Link  Locator is	between	the device and the master, the locator
       field will be all FF.
       r locator is the	locator	in reverse order.

   present (DEPRECATED)
       read-only, yes-no
       Is the device currently present on the 1-wire bus?

   type
       read-only, ascii
       Part name assigned by Dallas Semi. E.g.	DS2401	Alternative  packaging
       (iButton	vs chip) will not be distiguished.

ALARMS
       Use the set_alarm property to set the alarm triggering criteria.

DESCRIPTION
   1-Wire
       1-wire is a wiring protocol and series of devices designed and manufac-
       tured by	Dallas Semiconductor, Inc. The bus is  a  low-power  low-speed
       low-connector scheme where the data line	can also provide power.

       Each  device  is	 uniquely and unalterably numbered during manufacture.
       There are a wide	variety	of devices, including memory, sensors  (humid-
       ity, 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 en-
       cryption	included.

       The 1-wire scheme uses a	single bus master and multiple slaves  on  the
       same  wire.  The	bus master initiates all communication.	The slaves can
       be individually discovered and addressed	using their unique ID.

       Bus masters come	in a variety of	configurations including serial,  par-
       allel, i2c, network or USB adapters.

   OWFS	design
       OWFS  is	 a  suite of programs that designed to make the	1-wire bus and
       its devices easily accessible. The underlying priciple is to  create  a
       virtual filesystem, with	the unique ID being the	directory, and the in-
       dividual	properties of the device are represented as simple files  that
       can be read and written.

       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 com-
       munication. Still the fundemental goal has been ease of use,  flexibil-
       ity and correctness rather than speed.

   DS28E04
       The DS28E04 (3) is a memory chip	that bends the unique addressing capa-
       bilities	of the 1-wire design. Some of the ID bits can be  assigned  by
       hardware.

ADDRESSING
       All  1-wire  devices are	factory	assigned a unique 64-bit address. This
       address is of the form:

       Family Code
	      8	bits

       Address
	      48 bits

       CRC    8	bits

       Addressing under	OWFS is	in hexidecimal,	of form:

	      01.123456789ABC

       where 01	is an example 8-bit family code, and 12345678ABC is an example
       48 bit address.

       The  dot	 is  optional,	and the	CRC code can included. If included, it
       must be correct.

DATASHEET
       http://pdfserv.maxim-ic.com/en/ds/DS28E04.pdf

SEE ALSO
   Programs
       owfs (1)	owhttpd	(1) owftpd (1)	owserver  (1)  owdir  (1)  owread  (1)
       owwrite (1) owpresent (1) owtap (1)

   Configuration and testing
       owfs (5)	owtap (1) owmon	(1)

   Language bindings
       owtcl (3) owperl	(3) owcapi (3)

   Clocks
       DS1427  (3)  DS1904(3)  DS1994  (3)  DS2404  (3)	DS2404S	(3) DS2415 (3)
       DS2417 (3)

   ID
       DS2401 (3) DS2411 (3) DS1990A (3)

   Memory
       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)

   Switches
       DS2405 (3) DS2406 (3) DS2408 (3)	DS2409 (3) DS2413 (3) DS28EA00 (3)

   Temperature
       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)

   Humidity
       DS1922 (3) DS2438 (3) EDS0065 (3) EDS0068 (3)

   Voltage
       DS2450 (3)

   Resistance
       DS2890 (3)

   Multifunction (current, voltage, temperature)
       DS2436  (3)  DS2437  (3)	 DS2438	 (3)  DS2751 (3) DS2755	(3) DS2756 (3)
       DS2760 (3) DS2770 (3) DS2780 (3)	DS2781 (3) DS2788 (3) DS2784 (3)

   Counter
       DS2423 (3)

   LCD Screen
       LCD (3) DS2408 (3)

   Crypto
       DS1977 (3)

   Pressure
       DS2406 (3) TAI8570 EDS0066 (3) EDS0068 (3)

   Moisture
       EEEF (3)	DS2438 (3)

AVAILABILITY
       http://www.owfs.org

AUTHOR
       Paul Alfille (paul.alfille@gmail.com)

OWFS Manpage			     2003			DS28E04-100(3)

NAME | SYNOPSIS | FAMILY CODE | SPECIAL PROPERTIES | STANDARD PROPERTIES | ALARMS | DESCRIPTION | ADDRESSING | DATASHEET | SEE ALSO | AVAILABILITY | AUTHOR

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