NEC mPD780973 Series Preliminary User's Manual page 232

(5) Prescaler mode register (PRM0)
This register specifies the valid edge for TI00/P40 to TI02/P42 pins input.
PRM0 is set with an 8-bit memory manipulation instruction.
RESET input sets this register to 00H.
Address: FF70H After Reset: 00H R/W
Symbol 7
PRM0 ES21
ES21
0
0
1
1
ES11
0
0
1
1
ES01
0
0
1
1
Caution Set the valid edge of the TI00/P40 to TI02/P42 pins after setting bit 2 of 16-bit timer mode
control register 0 (TMC0) to 0 to stop the timer operation.
232
CHAPTER 19 INTERRUPT FUNCTIONS
Figure 19-6. Prescaler Mode Register (PRM0) Format
6 5 4
ES20 ES11 ES10
ES20
0 Falling edge
1 Rising edge
0 Setting prohibited
1 Both rising and falling edges
ES10
0 Falling edge
1 Rising edge
0 Setting prohibited
1 Both rising and falling edges
ES00
0 Falling edge
1 Rising edge
0 Setting prohibited
1 Both rising and falling edges
3 2
ES01 ES00 PRM01
TI02 Valid Edge Selection
TI01 Valid Edge Selection
TI00 Valid Edge Selection
1 0
PRM00