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 externally, 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 hardware 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 determine
       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 optional. 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. Computed from the preceding 56 bits of the unique  ID	number.  Given	as
       upper 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 applications 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 manufactured 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 encryption 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, parallel, 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 individual 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 communication. Still the fundemental goal has  been  ease  of  use,
       flexibility and correctness rather than speed.

   DS28E04
       The DS28E04 (3) is a memory chip that bends the unique addressing capabilities 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)

   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)

AVAILABILITY

       http://www.owfs.org

AUTHOR

       Paul Alfille (paul.alfille@gmail.com)

OWFS Manpage							       2003							    DS28E04-100(3)