UPD78F0138 NEC, UPD78F0138 Datasheet - Page 157

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

(4) Prescaler mode register 0n (PRM0n)
Note The external clock requires a pulse two cycles longer than internal count clock (f
This register is used to set the 16-bit timer counter 0n (TM0n) count clock and TI00n and TI01n input valid edges.
PRM0n can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears PRM0n to 00H.
Remark n = 0:
Address: FFBBH
Symbol
PRM00
n = 0, 1:
PRM001
ES101
ES101
ES001
7
0
0
1
1
0
0
1
1
0
0
1
1
After reset: 00H
µ
µ
PD780131, 780132
PD780133, 780134, 78F0134, 780136, 780138, 78F0138
Figure 6-12. Format of Prescaler Mode Register 00 (PRM00)
CHAPTER 6 16-BIT TIMER/EVENT COUNTERS 00 AND 01
PRM000
ES100
ES000
ES100
6
0
1
0
1
0
1
0
1
0
1
0
1
R/W
Falling edge
Rising edge
Setting prohibited
Both falling and rising edges
Falling edge
Rising edge
Setting prohibited
Both falling and rising edges
f
f
f
TI000 valid edge
X
X
X
/2
/2
(10 MHz)
ES001
2
8
(2.5 MHz)
(39.06 kHz)
User’s Manual U16228EJ2V0UD
5
ES000
Note
4
TI010 valid edge selection
TI000 valid edge selection
Count clock selection
3
0
2
0
X
).
PRM001
1
PRM000
0
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