DS1427(3)

alarm

read-write, unsigned integer (0-111)
Alarm state of the DS2404 (3) triggered by time or counter events. Reading the alarm state clears the alarm.
The alarm value is of the form CIR, where:

C

cycle counter alarm
0 no
1 yes

I

interval timer alarm
0 no
1 yes

R

real-time clock alarm
0 no
1 yes

auto

read-write, yes-no
Flag for mode of interval counter operation. 0=manual 1=auto
See the datasheet for details.

date

read-write, ascii
26 character date representation of the udate value. Increments once per second while running
Actual internal representation has higher precision.
Cannot be altered if readonly/clock is set.
Setting date to a null string will put the current system time.
Accepted date formats are:
Sat[urday] March 12 12:23:59 2001
Apr[il] 4 9:34:56 2002
3/23/04 23:34:57
current locale setting (your system's format)

delay

read-write, yes-no
Flag for adding a delay to cycle counter. 0=short 1-long
See the datasheet under "IDEL" for details.

interval

read-write, date
Interval timer value, represented as a date string. More typically will be used as uinterval to read the actual elapsed seconds.

memory

read-write, binary
512 bytes of memory. The readonly/memory flag prevents further change.

pages/page.0 ... pages/page.15 pages/page.ALL

read-write, yes-no
Memory is split into 16 pages of 32 bytes each. The readonly/memory flag prevents further change. ALL is an aggregate of the pages. Each page is accessed sequentially.

readonly/[memory|clock|interval|cycle]

read-write, yes-no
Permanently protect part of the chip's function from alteration.

readonly/memory

page.X and memory

readonly/clock

date and udate

readonly/interval

interval

readonly/cycle

cycle

running

read-write, yes-no
State of the clock. 0=off 1=running.

set_alarm

read-write, unsigned integer (0-111)
Which of the alarm triggers are enabled in the DS2404 (3)
The set_alarm value is of the form CIR, where:

C

cycle counter alarm
0 no
1 yes

I

interval timer alarm
0 no
1 yes

R

real-time clock alarm
0 no
1 yes

start

read-write, yes-no
Flag for starting the interval counter operation if not in auto mode. 0=stop 1=start
See the datasheet for details.

trigger/[cycle,date,interval,udate,uinterval]

read-write,varies
Target value that will trigger the alarm if the corresponding set_alarm field is set.
The format is the same as the similarly named field (i.e. date for trigger/date )

udate

read-write, unsigned integer
Time represented as a number. udate increments once per second, while running is on.
Usually set to unix time standard: number of seconds since Jan 1, 1970. The date field will be the unix representation of udate and setting either will change the other.

uinterval

read-write, unsigned interval
Similar to the udate field, except corresponds to the interval value.

DS1427 DS1994 DS2404 DS2404S

The DS1427 (3), DS1994 (3), DS2404 (3), and DS2404S (3) family of 1-wire devices includes clock functions, with timers, memory, counters and alarms. It is possible to write-protect regians of memory. Uses include software or hardware timing and control.

Chips

Both the DS2404 (3) and DS2404S (3) have 1-wire and 3-wire interfaces, which might be useful for transferring data between the 2 buses. They act as a passive slave to both buses. The DS2404 (3) and DS2404S (3) require an external source of power and an external crystal. They also offer a reset and 1HZ clock pin.

iButtons

Both the DS1427 and DS1994 offer the memory, alarms, and clock function in iButton format. Because the iButton is a complete sealed package, battery and crystal are internal. Everything is access via the 1-wire interface.