M38C31M2AXXXFS View Datasheet(PDF) - Renesas Electronics

Part Name

Description

Manufacturer

M38C31M2AXXXFS

SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

Renesas Electronics 

APPLICATION

2.2 Timer

2.2.4 Notes on timer A (PWM mode and IGBT output mode)

(1) When timer starts first or last value of compare register is “000016”

After “L” level (timer A output active edge switch bit is “0”; when starting from “L” output) is output

during 2 cycles (until timer underflows two times), PWM output or IGBT output starts.

Reason: When data is written to timer A and compare register, value of timer A and value of

compare register are renewed at timer underflow. In case of this, compare register value

and timer value are compared before renewal, so that they are judged to be equal, and

TAOUT output becomes “L”. (Timer A output active edge switch bit = “0”: when starting from

“L” output)

Timer A underflow should cause “H” output, but the match have the priority. (see “Figure

2.2.29”)

Compare register value is

“000016”

(last value or initial value)

Compare register value is value which is written at Œ

Œ

Timer A start

Timer A underflow

Timer A value

compare register value

writing

Fig. 2.2.29 PWM output and IGBT output (1)

Timer A underflow

Timer A underflow

(2) When compare register is set to “000016” (last value is except “000016”)

Next 1 cycle of the cycle in which data is written to timer A and compare register is output “H”, and

“L” is output from the next cycle. (timer A output active edge switch bit = “0”: when starting from “L”

output)

(see “Figure 2.2.30”)

Compare register value is

last value

Compare register value is “000016”

Timer A underflow

Timer A underflow

Timer A value

compare register value

writing

Fig. 2.2.30 PWM output and IGBT output (2)

Timer A underflow

Timer A underflow

38C3 Group User’s Manual

2-31

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