Enhanced PWM (ePWM) Module
Table 15-60. Time-Base Control Register (TBCTL) Field Descriptions (continued)
Bit
Field
Value
Description
12:10
CLKDIV
0-7h
Time-base Clock Prescale Bits. These bits determine part of the time-base clock prescale value.
TBCLK = SYSCLKOUT/(HSPCLKDIV × CLKDIV)
0
/1 (default on reset)
1h
/2
2h
/4
3h
/8
4h
/16
5h
/32
6h
/64
7h
/128
9-7
HSPCLKDIV
0-7h
High-Speed Time-base Clock Prescale Bits. These bits determine part of the time-base clock
prescale value.
TBCLK = SYSCLKOUT/(HSPCLKDIV × CLKDIV)
This divisor emulates the HSPCLK in the TMS320x281x system as used on the Event Manager
(EV) peripheral.
0
/1
1h
/2 (default on reset)
2h
/4
3h
/6
4h
/8
5h
/10
6h
/12
7h
/14
6
SWFSYNC
Software Forced Synchronization Pulse
0
Writing a 0 has no effect and reads always return a 0.
1
Writing a 1 forces a one-time synchronization pulse to be generated.
This event is ORed with the EPWMxSYNCI input of the ePWM module.
SWFSYNC is valid (operates) only when EPWMxSYNCI is selected by SYNCOSEL = 00.
5-4
SYNCOSEL
0-3h
Synchronization Output Select. These bits select the source of the EPWMxSYNCO signal.
0
EPWMxSYNC:
1h
CTR = 0: Time-base counter equal to zero (TBCNT = 0000h)
2h
CTR = CMPB : Time-base counter equal to counter-compare B (TBCNT = CMPB)
3h
Disable EPWMxSYNCO signal
3
PRDLD
Active Period Register Load From Shadow Register Select
0
The period register (TBPRD) is loaded from its shadow register when the time-base counter,
TBCNT, is equal to zero.
A write or read to the TBPRD register accesses the shadow register.
1
Load the TBPRD register immediately without using a shadow register.
A write or read to the TBPRD register directly accesses the active register.
2
PHSEN
Counter Register Load From Phase Register Enable
0
Do not load the time-base counter (TBCNT) from the time-base phase register (TBPHS)
1
Load the time-base counter with the phase register when an EPWMxSYNCI input signal occurs or
when a software synchronization is forced by the SWFSYNC bit.
1583
SPRUH73H – October 2011 – Revised April 2013
Pulse-Width Modulation Subsystem (PWMSS)
Copyright © 2011–2013, Texas Instruments Incorporated