SPRUIW9C October 2021 – March 2024 TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1
The eQEP inputs include two pins for quadrature-clock mode or direction-count mode, an index (or 0 marker), and a strobe input. The eQEP module requires that the QEPA, QEPB, and QEPI inputs are synchronized to SYSCLK prior to entering the module. The application code can enable the synchronous GPIO input feature on any eQEP-enabled GPIO pins (see the General-Purpose Input/Output (GPIO) chapter for more details).
Input signals to the eQEP (QEPA, QEPB, QEPI and QEPS) can come from multiple sources; that is, device pin, CMPSSx, or PWMXBARx. One typical use case is if SinCos transducers are used in the motor control system to estimate the position of motor shaft and Index signal is coming from traditional rotary encoder, source of the eQEP signals (QEPA, QEPB and QEPI) can be configured as output of CMPSSx that decodes the Sin, Cos, and Index signals. Figure 23-4 illustrates the use case.
Selection of the source of Input signals (QEPA, QEPB, and QEPI) is user-configurable through the QEPSRCSEL register as shown in Table 23-1.
QEPASEL, QEPBSEL, QEPISEL | Input Signal |
---|---|
0 | INPUTXBAR |
1 | CMPSS1_CTRIPH |
2 | CMPSS2_CTRIPH |
3 | CMPSS3_CTRIPH |
4 | CMPSS4_CTRIPH |
5-7 | Reserved |
8 | ZERO |
9 | EPWMXBAR1 |
10 | EPWMXBAR2 |
11 | EPWMXBAR3 |
12 | EPWMXBAR4 |
13 | EPWMXBAR5 |
14 | EPWMXBAR6 |
15 | EPWMXBAR7 |