UPD784938 Datasheet, PDF (377/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 12 TIMER 3
(2) Prescaler mode register 0 (PRM0)
PRM0 specifies the count clock to timer 3 timer counter 3 (TM3/TM3W) by the high-order 4 bits (the low-order 4 bits
specify the count clock to timer/event counter 0 TM0).
PRM0 can be read and written with an 8-bit manipulation instruction. The format of the PRM0 is shown in
Figure 12-3.
RESET input sets PRM0 to 11H.
Figure 12-3. Prescaler Mode Register 0 (PRM0) Format
7
6
5
4
3
2
1
0 Address After reset R/W
PRM0 PRS3 PRS2 PRS1 PRS0 PRS03 PRS02 PRS01 PRS00 0FF5CH 11H R/W
Specifies count clock to timer/event counter 0 TM0 (see Figure 9-3).
PRS3 PRS2 PRS1 PRS0
(fXX = 12.58 MHz)
Timer 3 TM3/TM3W Count
Clock Specification
Count Clock [Hz]
Specification
Resolution
[ µs]
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
Other than the above
Setting prohibited
Preliminary User’s Manual U13987EJ1V0UM00
377