CHAPTER 6 16-BIT TIMER/EVENT COUNTER 00
User’s Manual U18172EJ2V0UD
90
Caution 6. When the TOE00 is 0, set the TOE00, LVS00, and LVR00 at the same time with the 8-bit
memory manipulation instruction. When the TOE00 is 1, the LVS00 and LVR00 can be set
with the 1-bit memory manipulation instruction.
(4) Prescaler mode register 00 (PRM00)
This register is used to set the 16-bit timer counter 00 (TM00) count clock and the TI000, TI010 pin input valid
edges.
PRM00 is set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation sets the value of PRM00 to 00H.
Figure 6-8. Format of Prescaler Mode Register 00 (PRM00)
Address: FF61H After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
PRM00 ES110 ES100 ES010 ES000
0
0 PRM001
PRM000
ES110
ES100
TI010 pin valid edge selection
0 0
Falling
edge
0 1
Rising
edge
1 0
Setting
prohibited
1
1
Both falling and rising edges
ES010
ES000
TI000 pin valid edge selection
0 0
Falling
edge
0 1
Rising
edge
1 0
Setting
prohibited
1
1
Both falling and rising edges
PRM001
PRM000
Count clock (f
sam
) selection
0 0
f
XP
(10 MHz)
0 1
f
XP
/2
2
(2.5 MHz)
1 0
f
XP
/2
8
(39.06 kHz)
1
1
TI000 pin valid edge
Note
Remarks 1.
f
XP
: Oscillation frequency of clock supplied to peripheral hardware
2.
( ): f
XP
= 10 MHz
Note
The external clock requires a pulse longer than two cycles of the internal count clock (f
XP
).
Cautions 1. Always set data to PRM00 after stopping the timer operation.
2. If the valid edge of the TI000 pin is to be set as the count clock, do not set the clear/start
mode and the capture trigger at the valid edge of the TI000 pin.