Each EPWM module has its own time-base submodule that determines all of the timing events. Built-in synchronization logic allows the time-base of multiple EPWM modules (EPWMx) to work together as a single system. Figure 12-176 illustrates the time-base module's place within the EPWM.
The TB module generates the period (or
frequency) of the PWM output waveforms and consists of a 16-bit counter that can be
configured for up, down or up and down counting. The time base for the counter is a
pre-scaled version of the system clock (FICLK/n) which can be programmed for a
pre-scale of 1, that is same as system clock.
TB module features:
- Specify the EPWMx time-base counter (TBCNT) frequency or period
in the EPWM_TBCNT register to control how often events occur.
- Manage time-base synchronization with other EPWMx modules.
- Maintain a phase relationship with other EPWMx modules.
- Set the time-base counter to count-up, count-down, or
count-up-and-down mode.
- Generate the following events:
- PRD_eq (Time-base counter
(EPWM_TBCNT register) equal to the specified period in EPWM_TBPRD
register (that is TBCNT = TBPRD)).
- CNT_zero (Time-base
counter equal to zero (TBCNT = 0000h)).
- Configure the rate of the time-base clock; a prescaled version
of the CPU m clock (FICLK). This allows the time-base counter to
increment/decrement at a slower rate.
The TB module generates the period (or
frequency) of the PWM output waveforms and consists of a 16-bit counter that can be
configured for up, down or up and down counting. The time base for the counter is a
pre-scaled version of the system clock (FICLK/n) which can be programmed for a
pre-scale of 1, that is same as system clock.
TB module features:
- Specify the EPWMx time-base counter (TBCNT) frequency or period in the
EPWM_TBCNT register to control how often events occur.
- Manage time-base synchronization with other EPWMx modules.
- Maintain a phase relationship with other EPWMx modules.
- Set the time-base counter to count-up, count-down, or count-up-and-down
mode.
- Generate the following events:
- PRD_eq (Time-base counter
(EPWM_TBCNT register) equal to the specified period in EPWM_TBPRD
register (that is TBCNT = TBPRD)).
- CNT_zero (Time-base
counter equal to zero (TBCNT = 0000h)).
- Configure the rate of the time-base clock; a prescaled version of the CPU m
clock (FICLK). This allows the time-base counter to increment/decrement at a
slower rate.