UPD70F3116 Datasheet, PDF (306/826 Pages) NEC – 32-Bit Single-Chip Microcontrollers

CHAPTER 9 TIMER/COUNTER FUNCTION
(6) Prescaler mode registers 10, 11 (PRM10, PRM11)
The PRM1n register is used to perform the following selections.
• Selection of count clock in the general-purpose timer mode (CMD bit of TUMn register = 0)
• Selection of count operation mode in the UDC mode (CMD bit = 1)
PRM1n can be read/written in 8-bit or 1-bit units.
Cautions 1. Overwriting the PRM1n register during TM1n operation (TM1CEn bit = 1) is prohibited.
2. Clearing the PRM12 bit to 0 is prohibited in UDC mode (CMD bit of TUMn register = 1).
3. When TM1n is in mode 4, specification of the valid edge for the TIUD1n and TCUD1n
pins is invalid.
7
6
5
4
3
2
1
0
Address Initial value
PRM10
0
0
0
0
0
PRM12 PRM11 PRM10 FFFFF5EEH
07H
7
6
5
4
3
2
1
0
Address Initial value
PRM11
0
0
0
0
0
PRM12 PRM11 PRM10 FFFFF60EH
07H
Bit position
2 to 0
Bit name
PRM12 to
PRM10
Function
Specifies the up/down count operation mode during input of the clock rate when the
internal clock of the TM1n is used, or during external clock (TIUD1n) input.
PRM12 PRM11 PRM10
CMD = 0
Count clock
0
0
0
Setting
prohibited
0
0
1
fCLK/2
0
1
0
fCLK/4
0
1
1
fCLK/8
1
0
0
fCLK/16
1
0
1
fCLK/32
1
1
0
fCLK/64
1
1
1
fCLK/128
Remarks 1. fCLK: Base clock
2. n = 0, 1
CMD = 1
Count clock UDC mode
Setting prohibited
TIUD1n
Mode 1
Mode 2
Mode 3
Mode 4
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User’s Manual U14492EJ5V0UD