upd78f0103hmca1-5a4-a Renesas Electronics Corporation., upd78f0103hmca1-5a4-a Datasheet - Page 149

• Manufacturer Part Number: upd78f0103hmca1-5a4-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

7.4.2 Operation as external event counter
counter 50 (TM50).
Either the rising or falling edge can be selected.
and an interrupt request signal (INTTM50) is generated.
The external event counter counts the number of external clock pulses to be input to the TI50 pin by 8-bit timer
TM50 is incremented each time the valid edge specified by timer clock selection register 50 (TCL50) is input.
When the TM50 count value matches the value of 8-bit timer compare register 50 (CR50), TM50 is cleared to 0
Whenever the TM50 count value matches the value of CR50, INTTM50 is generated.
<1> Set each register.
<2> When TCE50 = 1 is set, the number of pulses input from the TI50 pin is counted.
<3> When the values of TM50 and CR50 match, INTTM50 is generated (TM50 is cleared to 00H).
<4> After these settings, INTTM50 is generated each time the values of TM50 and CR50 match.
Setting
TM50 count value
• Set port mode register 1 (PM17) to 1.
• TCL50: Select TI50 pin edge.
• CR50:
• TMC50: Stop the count operation, select clear & start mode entered on match of TM50 and CR50,
INTTM50
TI50 pin falling edge → TCL50 = 00H
TI50 pin rising edge → TCL50 = 01H
N = 00H to FFH
Figure 7-8. External Event Counter Operation Timing (with Rising Edge Specified)
CR50
TI50
Compare value
disable the timer F/F inversion operation, disable timer output.
(TMC50 = 0000××00B × = Don’t care)
Count start
00H
01H
CHAPTER 7 8-BIT TIMER/EVENT COUNTER 50
02H
03H
User’s Manual U16846EJ3V0UD
04H
05H
N–1
N
N
00H
01H
02H
03H
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