SH7041A datasheet(441/923 Pages) RENESAS

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When TCNT3 and TCNT4 count up to H'FFFF, a compare-match occurs with TGR3A, and

TCNT3 and TCNT4 are both cleared. At this point, TSR3’s TCFV bit is not set, but the TCFV bit

of TSR4 is set.

This can be avoided by sync setting for channel 3 and channel 4. Set the SYNC3 and SYNC4 bits

of the timer sync register (TSYR) to 1, compare-match with TGR3A by TCR3 for the counter

clear source, and sync clear with TCR4. This gives the sync setting for channels 3 and 4.

Figure 12.89 shows a TCFV bit operation example in reset sync PWM mode with a set value for

cycle register TGR3A of H'FFFF, when a TGR3A compare-match has been specified without

synchronous setting for the counter clear source.

TGR3A

(H'FFFF)

H'0000

TCF3V

TCF4V

TCNT3 = TCNT4

Counter cleared by compare match A3

Not set

Set

Figure 12.89 Reset Sync PWM Mode Overflow Flag

• A mask operation

For A mask, the above operation is modified as follows:

When set to reset sync PWM mode, TCNT3 and TCNT4 start counting when the CST3 bit of

TSTR is set to 1. At this point, TCNT4’s count clock source and count edge obey the TCR3

setting.

In reset sync PWM mode, with cycle register TGR3A’s set value at H'FFFF and specifying

TGR3A compare-match for the counter clear source, the operation of the overflow flag TCFV

bit for both TSR3 and TSR4 will be the same.

When TCNT3 and TCNT4 count up to H'FFFF, a compare-match occurs with TGR3A, and

TCNT3 and TCNT4 are both cleared. At this point, TCFV bits for TSR3 and TSR4 are not set.

Figure 12.90 shows a TCFV bit operation example in reset sync PWM mode with a set value

for cycle register TGR3A of H'FFFF, when a TGR3A compare-match has been specified

without synchronous setting for the counter clear source.

SH7041A Datasheet(PDF) 441 Page - Renesas Technology Corp