UPD78F0838 Renesas Electronics Corporation., UPD78F0838 Datasheet - Page 324

• Manufacturer Part Number: UPD78F0838
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

7.4.2 Operation as external event counter
counter 5n (TM5n).
Either the rising or falling edge can be selected.
and an interrupt request signal (INTTM5n) is generated.
322
The external event counter counts the number of external clock pulses to be input to the TIO5n pin by 8-bit timer
TM5n is incremented each time the valid edge specified by timer clock selection register 5n (TCL5n) is input.
When the TM5n count value matches the value of 8-bit timer compare register 5n (CR5n), TM5n is cleared to 0
Whenever the TM5n value matches the value of CR5n, INTTM5n is generated.
<1> Set each register.
<2> When TCE5n = 1 is set, the number of pulses input from the TIO5n pin is counted.
<3> When the values of TM5n and CR5n match, INTTM5n is generated (TM5n is cleared to 00H).
<4> After these settings, INTTM5n is generated each time the values of TM5n and CR5n match.
Setting
TM5n count value
Note 8-bit timer/event counter 50: PM02
Remark N = 00H to FFH
8-bit timer/event counter 51: PM03
INTTM5n
Set the port mode register (PM02 or PM03)
TCL5n: Select TIO5n pin input edge.
CR5n:
TMC5n: Stop the count operation, select the mode in which clear & start occurs on match of TM5n and
Figure 7-11. External Event Counter Operation Timing (with Rising Edge Specified)
TIO5n
CR5n
n = 0, 1
TIO5n pin falling edge
TIO5n pin rising edge
Compare value
CR5n, disable the timer F/F inversion operation, disable timer output.
(TMC5n = 0000
Count start
00
CHAPTER 7 8-BIT TIMER/EVENT COUNTERS 50 AND 51
01
02
00B
Preliminary User’s Manual U19748EJ1V0UD
03
TCL5n = 01H
TCL5n = 00H
= Don’t care)
04
Note
05
to 1.
N – 1
N
N
00
01
02
03