Datasheet

78K0/Ix2 CHAPTER 7 16-BIT TIMER/EVENT COUNTER 00
R01UH0010EJ0500 Rev.5.00 264
Feb 28, 2012
Figure 7-9. Format of Prescaler Mode Register 00 (PRM00)
(1) 78K0/IY2, 78K0/IA2, 78K0/IB2 (32 pins)
Address: FFBBH After reset: 00H R/W
Symbol 7 6 5 4 3 2 1 0
PRM00 0 0 ES010 ES000 0 0 PRM001 PRM000
(2) 78K0/IB2 (30 pins)
Address: FFBBH 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
Count clock selection PRM001 PRM000
f
PRS = 2 MHz fPRS = 5 MHz fPRS = 10 MHz fPRS = 20 MHz
(When using
the PLL)
0 0 fPRS 2 MHz 5 MHz 10 MHz 20 MHz
0 1 fPRS/2
2
500 kHz 1.25 MHz 2.5 MHz 5 MHz
1 0 fPRS/2
8
7.81 kHz 19.53 kHz 39.06 kHz 78.13 kHz
1 1 TI000 valid edge
Notes 1, 2
Notes 1. If the peripheral hardware clock (f
PRS) operates on the high-speed system clock (fXH) (XSEL = 1), the fPRS
operating frequency varies depending on the supply voltage.
2. The external clock from the TI000 pin requires a pulse longer than twice the cycle of the peripheral
hardware clock (f
PRS).
Caution If the peripheral hardware clock (f
PRS) operates on the high-speed system clock (fXH) (XSEL = 1), the fPRS
operating frequency varies depending on the supply voltage.
Remark f
PRS: Peripheral hardware clock frequency