SH7041A datasheet(400/923 Pages) RENESAS

400 / 923 page

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• Register data updating

In complementary PWM mode, the buffer register is used to update the data in a compare

duty and carrier cycle registers that have buffer registers and can be updated during operation.

There is a temporary register between each of these registers and its buffer register. When

subcounter TCNTS is not counting, if buffer register data is updated, the temporary register

value is also rewritten. Transfer is not performed from buffer registers to temporary registers

when TCNTS is counting; in this case, the value written to a buffer register is transferred after

TCNTS halts.

The temporary register value is transferred to the compare register at the data update timing set

with bits MD3–MD0 in the timer mode register (TMDR). Figure 12.42 shows an example of

data updating in complementary PWM mode. This example shows the mode in which data

updating is performed at both the counter crest and trough.

When rewriting buffer register data, a write to TGR4D must be performed at the end of the

update. Data transfer from the buffer registers to the temporary registers is performed

simultaneously for all five registers after the write to TGR4D.

A write to TGR4D must be performed after writing data to the registers to be updated, even

when not updating all five registers, or when updating the TGR4D data. In this case, the data

written to TGR4D should be the same as the data prior to the write operation.

SH7041A Datasheet(PDF) 400 Page - Renesas Technology Corp