Siemens Simatic S5 PG 730 Systemhandbuch Seite 110

ROM-BIOS
I N T 1A
time_of_day
this routine allows the clock to be set/read
input
(ah) = 0
(ah) = 1
note: counts occur at the rate of 1193180/65536 counts/sec
(or about 18.2 per second)
(ah) = 2
(ah) = 3
(dl) = 1
(ah) = 4
(ah) = 5
(ah) = 6
7 - 30
read the current clock setting
returns cx = high portion of count
dx = low portion of count
al = 0 if timer has not passed 24 hour
since last read. 0 if on another day
set the current clock
cx = high portion of count
dx = low portion of count
read the real time clock
returns ch = hours in bcd
cl = minutes in bcd
dh = seconds in bcd
set the real time clock
ch = hours in bcd
cl = minutes in bcd
dh = seconds in bcd
if daylight savings time option, else 0
read the date from the real time clock
returns ch = century in bcd (19 or 20)
cl = year in bcd
dh = month in bcd
dl = day in bcd
set the date into the real time clock
ch = century in bcd (19 or 20)
cl = year in bcd
dh = month in bcd
dl = day in bcd
set the alarm
the alarm can be set to interrupt up to
23:59:59 from present time.
one alarm function can be active at any time
Systemhandbuch
C79000-B8500-C073-01