UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 229

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

CHAPTER 8 TIMER/COUNTER 0
Caution When timer/counter 0 is used as an external event counter, it is not possible to distinguish between the
case where there is no valid edge input at all and the case where there is a single valid edge input, using
the timer register 0 (TM0) alone (see Figure 8-11), since the contents of TM0 are 0 in both cases. If it is
necessary to make this distinction, the INTP3 interrupt request flag should be used. An example is shown
in Figure 8-12.
Figure 8-11 Example of the Case Where the External Event Counter Does Not Distinguish Between One
Valid Edge Input and No Valid Edge Input
INTP3
TM0
0
0
1
2
No Distinction Made
Count Start
189