NEC Renesas V850/SC1 User Manual page 272

(7) Prescaler mode registers 90, 91, 110, 111 (PRM90, PRM91, PRM110, PRM111)
PRM1n selects the count clock of the 16-bit timer (TM9, TM11) and the valid edge of the TIn0 and TIn1 inputs.
PRMn0 and PRMn1 are set by an 8-bit memory manipulation instruction (n = 9, 11).
RESET input clears PRMn0 and PRMn1 to 00H.
After reset: 00H R/W
PRMn1
(n = 9, 11)
After reset: 00H R/W
7
PRMn0 ESn11
(n = 9, 11)
ESn11
0
0
1
1
ESn01
0
0
1
1
PRMn2
0
0
0
0
1
1
1
1
Note A pulse longer than twice the internal clock (f
270
CHAPTER 8 TIMER/COUNTER FUNCTION
Address: FFFFF3BEH, FFFFF0EEH
7 6 5
0 0 0
Address: FFFFF3B6H, FFFFF0E6H
6 5
ESn10 ESn01
ESn10
0 Falling edge
1 Rising edge
0 Setting prohibited
1 Both rising and falling edges
ESn00
0 Falling edge
1 Rising edge
0 Setting prohibited
1 Both rising and falling edges
PRMn1 PRMn0
0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1
User's Manual U15109EJ3V0UD
4 3 2
0 0 0
4 3 2
ESn00 0 0
Selects valid edge of TIn1
Selects valid edge of TIn0
Count clock selection
Count clock
20 MHz
f /4 200 ns
;;
f /8 400 ns
;;
1.6 µ s
f /32
;;
490 −
TIn0 valid edge
3.2 µ s
f /64
;;
6.4 µ s
f /128
;;
25.6 µ s
f /512
;;
−
Setting prohibited
/2) is required for an external clock.
;;
1 0
0 PRMn2
1 0
PRMn1 PRMn0
f
;;
18.87 MHz 16 MHz
212 ns 250 ns
424 ns 500 ns
1.7 µ s 2 µ s
− −
3.4 µ s 4 µ s
6.8 µ s 8 µ s
27.1 µ s 32 µ s
− −