Toshiba H1 Series Data Book page 596

3.22.3.2 Alarm generator
The Alarm function generates eight kinds of alarm waveform having a modulation
frequency 4096Hz determined by the low-speed clock (32.768 KHz). And this waveform is
reversible by setting a value to a register.
By connecting a loud speaker outside, Alarm tone can easily sound.
Five kind of fixed cycles (1Hz, 2Hz, 64Hz, 512Hz, 8192Hz) interrupt be generate by using
a counter which is used for alarm generator.
(Operation)
At first, MELALMC<MELALM> have to be set as "0" in order to select alarm waveform
as output waveform from MLDALM. Then "10" be set on MELALMC<FC1:0> register, and
clear internal counter. Finally alarm pattern has to be set on 8-bit register of ALM. If it is
inverted output-data, set <ALMINV> as invert.
Followings are example program, setting value of alarm pattern and waveform of each
setting value.
(Setting value of alarm pattern)
Setting value
for ALM
register
00H
01H
02H
04H
08H
10H
20H
40H
80H
Other
(Example program)
In case of outputting AL2 pattern (31.25ms/8 times/1sec)
Alarm waveform
"0" fixed
AL1 pattern
AL2 pattern
AL3 pattern
AL4 pattern
AL5 pattern
AL6pattern
AL7 pattern
AL8 pattern
Undefined
(Do not set)
LD (MELALMC), C0H
LD (ALM), 02H
92CZ26A-593
; Set output alarm waveform
; Free-run counter start
; Set AL2 pattern, start
TMP92CZ26A