HD404369 Datasheet, PDF (83/117 Pages) Hitachi Semiconductor – 4-bit HMCS400-Series microcomputer

HD404369 Series
Port Mode Register C (PMRC: $025): This register has the following functions (figure 63).
• Prescaler division ratio selection
• Output level control in idle states
Port mode register C (PMRC: $025) is a 4-bit write-only register. It cannot be written during data transfer.
By setting bit 0 (PMRC0) of this register, the prescaler division ratio is selected. Bit 0 (PMRC0) can be
reset to 0 by MCU reset. By setting bit 1 (PMRC1), the output level of the SO pin is controlled in idle
states. The output level changes at the same time that PMRC1 is written to.
Port mode register C (PMRC: $025)
Bit
Initial value
Read/Write
Bit name
3
0
W
PMRC3
2
1
0
0 Undefined 0
W
W
W
PMRC2 PMRC1 PMRC0
Alarm output function.
Refer to figure 57.
PMRC0
0
1
Serial Clock Division Ratio
Prescaler output divided by 2
Prescaler output divided by 4
PMRC1
0
1
Output Level Control in Idle States
Low level
High level
Figure 63 Port Mode Register C (PMRC)
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