tms320c6455dsk: muxed gpio/mcbsp1 pins to be used as gpio on J3 connector

Hello everybody,

I'm working on a TMS320C6455 DSK board and I want to use the muxed GPIO/McBSP1 pins as GPIO, for both input and output. As a test I tried to toggle one of those pins in order to have a pseudo-clock signal on the pins of the J3 connector that are shared by GPIO and McBSP1 interfaces. Since the latter is enabled at startup of the board and is set to communicate with the AIC23 audio codec ("on-board" setting), I set the proper CPLD register in order to create a path between the muxed pins and the connector ("off-board" setting)and then I disabled the McBSP1 interface by setting the corresponding field in PERCFG0 register.
I used the following code:

//off-board setting
do{
DSK6455_rset(DSK6455_MISC, 0x01);
}while(DSK6455_rget(DSK6455_MISC) != 1);

//McBSP1 disabled
CSL_FINST(((CSL_DevRegs *)CSL_DEV_REGS)->PERLOCK, DEV_PERLOCK_LOCKVAL, UNLOCK);
CSL_FINS(((CSL_DevRegs *)CSL_DEV_REGS)->PERCFG0, DEV_PERCFG0_MCBSP1CTL, 0x00000000);

//Enable, init, open, setup for GPIO
...
CSL_GpioConfig gpioCfg = CSL_GPIO_CONFIG_DEFAULTS;
pinCfg.pinNum = (CSL_GpioPinNum)0;
pinCfg.direction = CSL_GPIO_DIR_OUTPUT;
pinCfg.trigger = CSL_GPIO_TRIG_CLEAR_EDGE;
...

//toggle GPIO pin GP[0]
while(1)
{
hGpio->regs->SET_DATA = 0x00000001;
hGpio->regs->CLR_DATA = 0x00000001;
}

I checked both the MISC register and the PERSTAT0 register after those changes and their values were the ones I expacted, but there's no signal on the J3 connector pins. I was able to toggle all GPIO pins on the HPI/PCI connector, so I think at least the GPIO code is ok.

Any advice for a way to get that signal on the connector pins?
Thanks in advance for any answer you'll provide,

Lee-Mort_Atchi

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