UPD784938 Datasheet, PDF (313/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 11 TIMER/EVENT COUNTER 2
(2) Prescaler mode register 1 (PRM1)
In PRM1, the count clock to timer/event counter 2 TM2/TM2W is specified by the high-order 4 bits (the low-order 4
bits specify the count clock to timer/event counter 1 TM1/TM1W).
PRM1 can be read or written with an 8-bit manipulation instruction. The format of PRM1 is shown in
Figure 11-3.
RESET input sets PRM1 to 11H.
Figure 11-3. Prescaler Mode Register 1 (PRM1) Format
7
6
5
4
3
2
1
0 Address After reset R/W
PRM1 PRS23 PRS22 PRS21 PRS20 PRS13 PRS12 PRS11 PRS10 0FF5EH 11H R/W
Specifies count clock to timer/event counter 1 (TM1/TM1W)
(see Figure 10-3).
(fXX = 12.58 MHz)
PRS23 PRS22 PRS21 PRS20 Timer/Event Counter 2 TM2/
TM2W Count Clock Specification
Count Clock [Hz]
Specification
Resolution
[ µ s]
0
0
0
0 _{Setting prohibited}
–
0
0
0
1 _fXX/4
0.32
0
0
1
0 _fXX/8
0.64
0
0
1
1 _fXX/16
1.27
0
1
0
0 _fXX/32
2.54
0
1
0
1 _fXX/64
5.09
0
1
1
0 _fXX/128
10.17
0
1
1
1 _fXX/256
20.35
1
0
0
0 _fXX/512
40.70
1
0
0
1 _fXX/1,024
81.40
1
1
1
1 _{External clock (CI/INTP2) –}
Other than the above
Setting prohibited
Remark fXX: X1 input frequency or oscillation frequency
Preliminary User’s Manual U13987EJ1V0UM00
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