upd78f0114hgb-8es-a Renesas Electronics Corporation., upd78f0114hgb-8es-a Datasheet - Page 134

• Manufacturer Part Number: upd78f0114hgb-8es-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

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(4) Prescaler mode register 00 (PRM00)
134
Notes 1.
Cautions 1. When the internal oscillation clock is selected as the clock to be supplied to the CPU, the
This register is used to set the 16-bit timer counter 00 (TM00) count clock and TI000 and TI010 pin input valid
edges.
PRM00 can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears PRM00 to 00H.
Address: FFBBH
Symbol
PRM00
2.
2. Always set data to PRM00 after stopping the timer operation.
3. If the valid edge of the TI000 pin is to be set for the count clock, do not set the clear & start
Be sure to set the count clock so that the following condition is satisfied.
The external clock requires a pulse two cycles longer than internal clock (f
V
V
V
V
clock of the internal oscillator is divided and supplied as the count clock. If the count clock
is the internal oscillation clock, the operation of 16-bit timer/event counter 00 is not
guaranteed.
selected and supplied to the CPU, the operation of 16-bit timer/event counter 00 is not
guaranteed, either, because the internal oscillation clock is supplied as the sampling clock to
eliminate noise.
mode using the valid edge of the TI000 pin and the capture trigger.
PRM001
DD
DD
DD
DD
ES101
ES101
ES001
= 4.0 to 5.5 V: Count clock
= 3.3 to 4.0 V: Count clock
= 2.7 to 3.3 V: Count clock
= 2.5 to 2.7 V: Count clock
7
0
0
1
1
0
0
1
1
0
0
1
1
After reset: 00H
Figure 6-8. Format of Prescaler Mode Register 00 (PRM00)
PRM000
ES100
ES000
ES100
When an external clock is used and when the internal oscillation clock is
6
0
1
0
1
0
1
0
1
0
1
0
1
CHAPTER 6 16-BIT TIMER/EVENT COUNTER 00
R/W
Falling edge
Rising edge
Setting prohibited
Both rising and falling edges
Falling edge
Rising edge
Setting prohibited
Both rising and falling 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 U16961EJ4V0UD
5
10 MHz
8.38 MHz
5 MHz
2.5 MHz (standard products, (A) grade products only)
ES000
Note 2
4
TI010 pin valid edge selection
TI000 pin valid edge selection
Count clock selection
3
0
2
0
Note 1
X
).
PRM001
1
PRM000
0