CHAPTER 9 TIMER/COUNTER FUNCTION
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User’s Manual U15195EJ5V0UD
(4) PWM mode 2: Sawtooth wave modulation
[Setting procedure]
(a) Set PWM mode 2 (sawtooth wave) using the MOD01 and MOD00 bits of the TMC0n register. Also set
the active level of the TO0n0 to TO0n5 pins using the ALVTO bit of the TOMRn register.
(b) Set the count clock of TM0n using the PRM02 to PRM00 bits of the TMC0n register. The transfer
operation from BFCMn3 to CM0n3 is set using the BFTE3 bit, and the transfer operation from BFCMn0 to
BFCMn2, BFCMn4, and BFCMn5 to CM0n0 to CM0n2, CM0n4, and CM0n5 is set using the BFTEN bit.
(c) Set the initial values.
(i) Specify the interrupt culling ratio using the CUL02 to CUL00 bits of the TMC0n register.
(ii) Set the cycle width of the PWM cycle in BFCMn3.
•
PWM cycle = (BFCMn3 value + 1)
×
TM0n count clock
(The TM0n count clock is set by the TMC0n register.)
(iii) Set the dead-time width in DTRRn.
•
Dead-time width = (DTRRn + 1)/f
CLK
f
CLK
: Base clock
(iv) Set the set/reset timing of the F/F used in the PWM cycle in BFCM0n0 to BFCM0n2.
(d) Clear (0) the TM0CEDn bit of the TMC0n register to enable dead-time timer operation. Set TM0CEDn =
1 when not using dead time.
(e) Setting (1) the TM0CEn bit of the TMC0n register starts TM0n counting, and a 6-channel PWM signal is
output from pins TO0n0 to TO0n5.
Caution Setting CM0n3 to 0000H is prohibited.
Содержание PD703114
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