CHAPTER 7 TIMER/COUNTER FUNCTION
User’s Manual U13850EJ6V0UD
210
(5) Prescaler mode registers 10, 11 (PRM10, PRM11)
PRM1n selects the count clock of the 16-bit timer (TM1) and the valid edge of TI1n input. PRM10 and PRM11
are set by an 8-bit memory manipulation instruction.
RESET input clears PRM10 and PRM11 to 00H.
After reset: 00H R/W
Address: FFFFF216H
7
6
5
4
3
2
1
0
PRM10
ES111
ES110
ES101
ES100
0
0
PRM11
PRM10
After reset: 00H R/W
Address: FFFFF21EH
7
6
5
4
3
2
1
0
PRM11
0
0
0
0
0
0
0
PRM12
ES111
ES110
Selection of valid edge of TI11
0
0
Falling edge
0
1
Rising edge
1
0
Setting prohibited
1
1
Both rising and falling edges
ES101
ES100
Selection of valid edge of TI10
0
0
Falling edge
0
1
Rising edge
1
0
Setting prohibited
1
1
Both rising and falling edges
Count clock selection
f
XX
PRM12
PRM11
PRM10
Count clock
20 MHz
Note 2
12.58 MHz
0
0
0
f
XX
/2
100 ns
158 ns
0
0
1
f
XX
/4
200 ns
318 ns
0
1
0
f
XX
/16
800 ns
1.3
µ
s
0
1
1
TI10 valid edge
Note 1
−
−
1
0
0
f
XX
/32
1.6
µ
s
2.5
µ
s
1
0
1
f
XX
/128
6.4
µ
s
10.2
µ
s
1
1
0
f
XX
/256
12.8
µ
s
20.3
µ
s
1
1
1
Setting prohibited
−
−
Notes 1.
The external clock requires a pulse longer than twice that of the internal clock (f
XX
/2).
2.
Only in the V850/SB1.
Cautions 1.
When selecting the valid edge of TI10 as the count clock, do not specify the clear & start
mode entered on the valid edge of TI10 or TI10 as a capture trigger.
2.
Before setting data to PRM1n, always stop the timer operation.
3.
If the 16-bit timer (TM1) operation is enabled by specifying the rising edge or both edges
as the valid edge of the TI1n pin while the TI1n pin is high level immediately after system
reset, the rising edge is detected immediately after the rising edge or both edges is
specified. Be careful when pulling up the TI1n pin. However, the rising edge is not
detected when operation is enabled after it has been stopped.
Содержание V850/SB1
Страница 2: ...User s Manual U13850EJ6V0UD 2 MEMO ...