Part Number:TMS320F28379D
Hello,
I'm working on a custom control board that will need EnDat interface and 2 resolvers. To have a very quick access to the dedicated resolver to digital parallel outputs I'm thinking to use the EMIF interface in an unconventional way. At the same time I would like to use the same emif1 to interface with an external flash memory. As a result I need all three chip select of the asynchronous interface (2 for the resolvers and 1 for the flash memory). EMI1CS2 can only be muxed on GPIO34.
According to sprui35 4.2.7 and 5 it seems that GPIO34 is the only possible choice for the EnDat Direction Control. At the same time sprui71 (about tformat, that is using the same interface) section 5 seems to say something different:
GPIO34 is used for this purpose on IDDK and
example projects. User can choose any GPIO with
OUTPUTXBAR1 mux option.
Do you confirm me that it is possible to use other pins instead of GPIO34? In that case, according to the fact that OUTPUTXBAR1 has to be used the other possible pins are: GPIO2, GPIO24, GPIO58.
I have another question about resource requirments of EnDAT/BiSSC/tformat interface: in the respective sprui it appears that EPWM4 is dedicated for clock generation. However, in the initialization process it seems that registers of other EPWM has to be modified:
SPRUI35 (EnDat) 4.2.5
Enable clocks to EPWM Instances 1, 2, 3 and 4.
CpuSysRegs.PCLKCR2.bit.EPWM1 = 1;
CpuSysRegs.PCLKCR2.bit.EPWM2 = 1;
CpuSysRegs.PCLKCR2.bit.EPWM3 = 1;
CpuSysRegs.PCLKCR2.bit.EPWM4 = 1;
SPRUI71 (tformat) 4.2.4
Enable clocks to EPWM Instances 1, 2, 3 and 4.
tformatData.spi = &SpibRegs;
PM_tformat_setupPeriph();
SPRUI37 (BiSSC) 4.2.6
Enable clocks to EPWM Instances 3 and 4:
CpuSysRegs.PCLKCR2.bit.EPWM3 = 1;
CpuSysRegs.PCLKCR2.bit.EPWM4 = 1;
So the second question is: why do I have to modify registers of other EPWM than the numeber 4? Will I be free to use EPWM1 2 and 3 without any kind of limitation while using the interface for EnDat/tformat/BiSSc? that question is relevant, because I need to use at least 18 PWM channels at the same time, so I need at least 9 dedicated EPWM periferrals.
I also have a third question that is of lower importance. Is that possible in some way to have more than one EnDat encoder connected? I was thinking about routing some signals. A possible way can be to have two indipendent interfaces and to route EnDatclk, SPISIMO,SPISOMI and direction control by means of some dedicated integrated circuit. Do you think this solution can be feasable?
Thanks in advance