CHAPTER 6 16-BIT TIMER/EVENT COUNTER 00
Preliminary User’s Manual U16846EJ1V0UD
113
(4) Prescaler mode register 00 (PRM00)
This register is used to set the 16-bit timer counter 00 (TM00) count clock and the valid edges of the TI000 and
TI010 pin input.
PRM00 can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears PRM00 to 00H.
Figure 6-8. Format of Prescaler Mode Register 00 (PRM00)
Address: FFBBH After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
PRM00 ES101 ES100 ES001 ES000
0
0 PRM001
PRM000
ES101
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
ES001
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
Note 1
0 0
f
X
(10 MHz)
0 1
f
X
/2
2
(2.5 MHz)
1 0
f
X
/2
8
(39.06 kHz)
1
1
TI000 pin valid edge
Note 2
Notes 1. Be sure to set the count clock so that the following condition is satisfied.
•
V
DD
= 4.0 to 5.5 V: Count clock
≤
10 MHz
•
V
DD
= 3.3 to 4.0 V: Count clock
≤
8.38 MHz
•
V
DD
= 2.7 to 3.3 V: Count clock
≤
5 MHz
2. The external clock requires a pulse two cycles longer than the internal clock (f
X
).