Clr
Set
Latch
QFRC:PCE
PCE
QCLR:PCE
QFLG:PCE
QEINT:PCE
QCLR:UTO
QFRC:UTO
QEINT:UTO
set
Latch
clr
UTO
QFLG:UTO
0
1
0
Pulse
generator
when
input=1
QFLG:INT
Latch
Set
Clr
QCLR:INT
EQEPxINT
QFLG:UTO
QUPRD
32
QUTMR
32
QEPCTL:UTE
UTIME
SYSCLKOUT
UTOUT
Enhanced Quadrature Encoder Pulse (eQEP) Module
15.4.2.7 Unit Timer Base
The eQEP peripheral includes a 32-bit timer (QUTMR) that is clocked by SYSCLKOUT to generate
periodic interrupts for velocity calculations. The unit time out interrupt is set (QFLG[UTO]) when the unit
timer (QUTMR) matches the unit period register (QUPRD).
The eQEP peripheral can be configured to latch the position counter, capture timer, and capture period
values on a unit time out event so that latched values are used for velocity calculation as described in
Section
.
Figure 15-147. eQEP Unit Time Base
15.4.2.8 eQEP Interrupt Structure
shows how the interrupt mechanism works in the EQEP module.
Figure 15-148. EQEP Interrupt Generation
Eleven interrupt events (PCE, PHE, QDC, WTO, PCU, PCO, PCR, PCM, SEL, IEL, and UTO) can be
generated. The interrupt control register (QEINT) is used to enable/disable individual interrupt event
sources. The interrupt flag register (QFLG) indicates if any interrupt event has been latched and contains
the global interrupt flag bit (INT). An interrupt pulse is generated only to the interrupt controller if any of the
interrupt events is enabled, the flag bit is 1 and the INT flag bit is 0. The interrupt service routine will need
to clear the global interrupt flag bit and the serviced event, via the interrupt clear register (QCLR), before
any other interrupt pulses are generated. You can force an interrupt event by way of the interrupt force
register (QFRC), which is useful for test purposes.
1670
Pulse-Width Modulation Subsystem (PWMSS)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated