Enhanced PWM (ePWM) Module
15.2.4.6.2 Event-Trigger Prescale Register (ETPS)
The event-trigger prescale register (ETPS) is shown in
and described in
Figure 15-92. Event-Trigger Prescale Register (ETPS)
15
4
3
2
1
0
Reserved
INTCNT
INTPRD
R-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 15-87. Event-Trigger Prescale Register (ETPS) Field Descriptions
Bits
Name
Value
Description
15-4
Reserved
0
Reserved
3-2
INTCNT
0-3h
ePWM Interrupt Event (EPWMx_INT) Counter Register. These bits indicate how many selected
ETSEL[INTSEL] events have occurred. These bits are automatically cleared when an interrupt pulse is
generated. If interrupts are disabled, ETSEL[INT] = 0 or the interrupt flag is set, ETFLG[INT] = 1, the
counter will stop counting events when it reaches the period value ETPS[INTCNT] = ETPS[INTPRD].
0
No events have occurred.
1h
1 event has occurred.
2h
2 events have occurred.
3h
3 events have occurred.
1-0
INTPRD
0-3h
ePWM Interrupt (EPWMx_INT) Period Select. These bits determine how many selected
ETSEL[INTSEL] events need to occur before an interrupt is generated. To be generated, the interrupt
must be enabled (ETSEL[INT] = 1). If the interrupt status flag is set from a previous interrupt
(ETFLG[INT] = 1) then no interrupt will be generated until the flag is cleared via the ETCLR[INT] bit.
This allows for one interrupt to be pending while another is still being serviced. Once the interrupt is
generated, the ETPS[INTCNT] bits will automatically be cleared.
Writing a INTPRD value that is the same as the current counter value will trigger an interrupt if it is
enabled and the status flag is clear.
Writing a INTPRD value that is less than the current counter value will result in an undefined state.
If a counter event occurs at the same instant as a new zero or non-zero INTPRD value is written, the
counter is incremented.
0
Disable the interrupt event counter. No interrupt will be generated and ETFRC[INT] is ignored.
1h
Generate an interrupt on the first event INTCNT = 01 (first event)
2h
Generate interrupt on ETPS[INTCNT] = 1,0 (second event)
3h
Generate interrupt on ETPS[INTCNT] = 1,1 (third event)
1601
SPRUH73H – October 2011 – Revised April 2013
Pulse-Width Modulation Subsystem (PWMSS)
Copyright © 2011–2013, Texas Instruments Incorporated