CHAPTER 6 16-BIT TIMER/EVENT COUNTER 00
User’s Manual U16898EJ3V0UD
91
(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 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
).