
361
•
PWM cycle setting
In complementary PWM mode, the PWM pulse cycle is set in two registers—TGR3A, in
which the TCNT3 upper limit value is set, and TCDR, in which the TCNT4 upper limit value
is set. The settings should be made so as to achieve the following relationship between these
two registers:
TGR3A set value = TCDR set value + TDDR set value
The TGR3A and TCDR settings are made by setting the values in buffer registers TGR3C and
TCBR. The values set in TGR3C and TCBR are transferred simultaneously to TGR3A and
TCDR in accordance with the transfer timing selected with bits MD3–MD0 in the timer mode
register (TMDR).
The updated PWM cycle is reflected from the next cycle when the data update is performed at
the crest, and from the current cycle when performed in the trough. Figure 12.41 illustrates the
operation when the PWM cycle is updated at the crest.
See the following section, Register data updating, for the method of updating the data in each
buffer register.
Counter value
TGR3C
update
TGR3A
update
TGR3A
TCNT3
TCNT4
Time
Figure 12.41 Example of PWM Cycle Updating
Summary of Contents for SH7041 Series
Page 2: ......
Page 6: ......
Page 38: ...xvi ...
Page 44: ...6 ...
Page 46: ...8 ...
Page 48: ...10 ...
Page 82: ...44 ...
Page 114: ...76 ...
Page 118: ...80 ...
Page 124: ...86 ...
Page 170: ...132 ...
Page 250: ...212 ...
Page 492: ...454 ...
Page 506: ...468 ...
Page 604: ...566 ...
Page 684: ...646 ...
Page 706: ...668 ...
Page 778: ...740 ...
Page 780: ...742 ...
Page 818: ...780 ...
Page 850: ...812 ...
Page 923: ...SH7040 SH7041 SH7042 SH7043 SH7044 SH7045 Group Hardware Manual REJ09B0044 0600O ...