Eqep Position-Compare Unit - Texas Instruments Concerto F28M36 Series Technical Reference Manual

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9.4.4 eQEP Position-compare Unit

The eQEP peripheral includes a position-compare unit that is used to generate a sync output and/or
interrupt on a position-compare match.
register is shadowed and shadow mode can be enabled or disabled using the QPOSCTL[PSSHDW] bit. If
the shadow mode is not enabled, the CPU writes directly to the active position compare register.
QPOSCTL:PCSHDW
QPOSCTL:PCLOAD
QPOSCMP
32
32
QPOSCNT
In shadow mode, you can configure the position-compare unit (QPOSCTL[PCLOAD]) to load the shadow
register value into the active register on the following events and to generate the position-compare ready
(QFLG[PCR]) interrupt after loading.
• Load on compare match
• Load on position-counter zero event
The position-compare match (QFLG[PCM]) is set when the position-counter value (QPOSCNT) matches
with the active position-compare register (QPOSCMP) and the position-compare sync output of the
programmable pulse width is generated on compare match to trigger an external device.
For example, if QPOSCMP = 2, the position-compare unit generates a position-compare event on 1 to 2
transitions of the eQEP position counter for forward counting direction and on 3 to 2 transitions of the
eQEP position counter for reverse counting direction (see
Figure 9-23 shows the layout of the eQEP Position-Compare Control Register (QPOSCTL) and
describes the QPOSCTL bit fields.
SPRUHE8E – October 2012 – Revised November 2019
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Figure 9-12
Figure 9-12. eQEP Position-compare Unit
QFLG:PCR
QFLG:PCM QPOSCTL:PCSPW
12
PCEVENT Pulse
stretcher
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Position Counter and Control Unit (PCCU)
shows a diagram. The position-compare (QPOSCMP)
QPOSCTL:PCPOL
0
1
Figure 9-13).
C28 Enhanced QEP (eQEP) Module
PCSOUT
Table 9-5
871