HD404339 Datasheet, PDF (49/78 Pages) Hitachi Semiconductor – 4-bit HMCS400-Series microcomputer with large-capacity memory

HD404339 Series
Alarm Output Function
The MCU has an alarm output function built in. By setting port mode register C (PMRC: $025), one of
four alarm frequencies supplied from the PSS can be selected.
BUZZ
Alarm output
controller
Alarm output
control signal
Port mode
register A
(PMRA)
Selector
2
System ^øPER
clock
Prescaler S (PSS)
Port mode
register C
(PMRC)
Table 9
PMRC
Bit 3
0
1
Figure 37 Alarm Output Function Block Diagram
Port Mode Register C
Bit 2
0
1
0
1
System Clock Divisor
÷ 2048
÷ 1024
÷ 512
÷ 256
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