DS28E04-100(3) One-Wire File System DS28E04-100(3)NAMEDS28E04 - 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 | ]]
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
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 PROPERTIESALARMS
Use the set_alarm property to set the alarm triggering criteria.
DESCRIPTIONDS28E04
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.
ADDRESSINGDATASHEET
http://pdfserv.maxim-ic.com/en/ds/DS28E04.pdf
SEE ALSOAVAILABILITY
http://www.owfs.org
AUTHOR
Paul Alfille (paul.alfille@gmail.com)
OWFS Manpage 2003 DS28E04-100(3)
