TMS320F28388D: Configuring gpio using Input Xbar registers

Subha R said:

gstrInputXbarRegs

Subha R said:

strECap7Regs

Have you renamed them?

Also one is the XBAR register one is the ECAP register. The two are not related.

Hi,

Yes, gstrInputXbarRegs and strECap7Regs are renamed. 

When I'm using this line alone, 'gstrInputXbarRegs.INPUT13SELECT = u16EcapPin; (gpio selection as user-input)'

module is working.

When I configure like below, as per TRM, the module is not working.

gstrGpioCtrlRegs.GPAPUD.bit.GPIO24 = 0; 

gstrGpioCtrlRegs.GPAQSEL2.bit.GPIO24 = 0; 

gstrInputXbarRegs.INPUT13SELECT = u16EcapPin;(here i took 24 for u16EcapPin as user input)

strECap7Regs.ECCTL0.bit.INPUTSEL = 13;

What is the reason?

Subha R said:

gstrGpioCtrlRegs.GPAPUD.bit.GPIO24 = 0; 

gstrGpioCtrlRegs.GPAQSEL2.bit.GPIO24 = 0; 

removing these two lines causes it work?

Hi Nima Eskandari

gstrGpioCtrlRegs.GPAPUD.bit.GPIO24 = 0; 

gstrGpioCtrlRegs.GPAQSEL2.bit.GPIO24 = 0; 

strECap7Regs.ECCTL0.bit.INPUTSEL = 13;

If I remove these 3 lines, it works.

But as per TRM of F28388D, these lines are necessary for ecap input selection. 

Can you try to see which one of the three lines is causing it? try removing them one at a time and try the code.

I tried it. 

strECap7Regs.ECCTL0.bit.INPUTSEL = 13;

This line causes issue. By default, value of ECCTL0.INPUTSEL is 0x7F. But when I configure it to 13(INPUTSEL13) or any other, it stops working.

Why do you set it to 13? What does 13 connect you to?

In Table 17-1 Input X-BAR Destinations from TRM of 2828x, any Ecap modules can use any INPUTSELECT registers. 

I use from INPUT7SELECT to INPUT13SELECT registers for ecap modules 1 to 7.

Thanks for the input. After changing to correct values in ECCTL0.INPUTSEL, modules are working.