SPRUI33H November 2015 – June 2024 TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1
Primary (data) filters can be synchronized with respect to the PWM event (called SDSYNC event). The SDSYNC signal from the PWM module is used to reset the DOSR counter. This feature is by default disabled and can be enabled by setting SDDFPARMx.SDSYNCEN = 1. Each primary filter can be synchronized from any of the available PWMx SOCA/SOCB signals (see Table 17-5). The SDSYNCx.SDSYNCSEL bits allow the user to configure which PWM signal provides the SDSYNC pulse to the primary filter. Figure 17-8 shows how device PWM signals are connected to the SDFM modules.
SDSYNCxSYNCSEL | Input Signal |
---|---|
0 | EPWM1_SOCA |
1 | EPWM1_SOCB |
2-3 | Reserved |
4 | EPWM2_SOCA |
5 | EPWM2_SOCB |
6-7 | Reserved |
8 | EPWM3_SOCA |
9 | EPWM3_SOCB |
10-11 | Reserved |
12 | EPWM4_SOCA |
13 | EPWM4_SOCB |
14-15 | Reserved |
16 | EPWM5_SOCA |
17 | EPWM5_SOCB |
18-19 | Reserved |
20 | EPWM6_SOCA |
21 | EPWM6_SOCB |
22-23 | Reserved |
24 | EPWM7_SOCA |
25 | EPWM7_SOCB |
26-27 | Reserved |
28 | EPWM8_SOCA |
29 | EPWM8_SOCB |
30-63 | Reserved |
Because of the inherent architecture of the Sinc filter (Sinc1, Sinc2, Sinc3, SincFast), the first few samples, depending upon filter type, are incorrect. Table 17-6 shows the number of incorrect samples on the following conditions:
Filter Type | Number of Incorrect Samples After the Filter is Enabled and Configured |
---|---|
Sinc1 | No incorrect sample. |
Sinc2 | The first sample of the Sinc2 filter is incorrect. |
SincFast | The first two samples of the SincFast filter are incorrect. |
Sinc3 | The first two samples of the Sinc3 filter are incorrect. |