UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 290

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

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(a) Processing when count is started
(b) Processing when count value is read
Figure 9-12 To Distinguish Whether One or No Valid Edge Has Been Input with External Event Counter
Read TM1 contents
Count value read
A
A
A = 0 ?
End
A + 1
TM1
NO
Clear INTP0 interrupt
YES
CHAPTER 9 TIMER/COUNTER 1
; Assign the number of input valid edges to A register
request flag
Start count
Start count
PIF0
CE1
End
YES
1
0
PIF0 = 1 ?
; Clear PIF0 to 0
; Set CE1 to 1
NO
; Check TM1 value
If 0, check interrupt
request flag
; Check PIF0 conents
If 1, there is a valid edge