C6678 EVM UART Receive Interrupt

Hi Murad,

CpIntc_postSysInt(0, 149); function is used for Writes the system interrupt number to the System Interrupt Status Index Set Register.

Without this mapping the interrupt is not initialized.

Thanks,

Thank you Ganapathi for your prompt response,

I will try to include CpIntc_postSysInt(0, 149);  in the initialization but from the sys/bios help, it says:

Writes the system interrupt number to the System Interrupt Status Index Set Register. Used for diagnostic and test purposes only.

I need real UART transactions, not just simulation!

Regards,

Murad

Anyone can help with this please...I read so many examples/documents but all describe what I have already...still can't get a UART receive interrupt?!?!

Regards,

Murad

Hi Murat,

Please take a look at below thread:

http://e2e.ti.com/support/dsp/c6000_multi-core_dsps/f/639/t/306806.aspx

 Thanks,

Thanks Ganapathi,

looking at your code and comparing it to the one in the platform folder void UartInit(void), I see that the following should enable the receive interrupt...but still no luck

int UART_init(void)



{



short int i;



Hwi_Params params;



Int hostInt, sysInt;



int eventId;



#if 0



(void) platform_uart_init();



// Allows access to the receiver buffer register (RBR),



// the transmitter holding register (THR), and the



// interrupt enable register (IER) selected.



//CSL_FINS (hUartRegs->LCR, UART_LCR_DLAB, CSL_UART_LCR_DLAB_DISABLE);



// No PARITY bit is transmitted or checked



CSL_FINS (hUartRegs->LCR, UART_LCR_PEN, CSL_UART_LCR_PEN_DISABLE);



// Disable THR, RHR, Receiver line status interrupts



CSL_FINS (hUartRegs->IER, UART_IER_ERBI, CSL_UART_IER_ERBI_ENABLE);//MQ



(void) platform_uart_set_baudrate(115200);



(void) platform_write_configure(PLATFORM_WRITE_ALL);







/*



* Map single sysInt to single hostInt and handle with a Hwi ISR.



* One-to-one mapping of sysInt to hostInt is more efficient than many



* to one routing since the BIOS CPINTC dispatcher keeps a table for



* the one-to-one mappings so that it doesn't have to query the h/w



* status registers for this information. Many-to-one interrupts have



* additional overhead since they cannot use this simple table lookup.



*/



#endif



//reset UART



hUartRegs->PWREMU_MGMT = 0x0;



(void) platform_uart_set_baudrate(115200);



hUartRegs->IER=0x03;



hUartRegs->MCR = 0;



hUartRegs->FCR = 0x7;



hUartRegs->PWREMU_MGMT = 0x6001;







sysInt = 149;



hostInt = 32;







　



　



/* convenience API to give GEM eventid for given host interrupt */



eventId = CpIntc_getEventId(hostInt);



/*



* Use GEM interrupt #5 to handle the hostInt associated with eventId.



*/



Hwi_Params_init(&params);



params.arg = hostInt;



params.eventId = eventId;



params.enableInt = TRUE;



params.priority = 2;



Hwi_create(5, &CpIntc_dispatch, &params, NULL);



// Hwi_enableInterrupt(5);



// Hwi_enable();







/*



* plug CpIntc dispatch table with 'UART_Rx_hwi'.



* set 'unmask' to 'TRUE' to enable the system interrupt.



*/



CpIntc_disableHostInt(0, hostInt);



CpIntc_disableSysInt(0, sysInt);



CpIntc_clearSysInt(0, sysInt);







CpIntc_mapSysIntToHostInt(0, sysInt, hostInt);



CpIntc_dispatchPlug(sysInt, UART_Rx_hwi, sysInt, TRUE);



CpIntc_enableHostInt(0, hostInt);



CpIntc_enableSysInt(0, sysInt);



　



return 1;



}



 

So the problem was not in the initializations above, it was in the system interrupt number 149. I changed it to 148 (since I am not using Event) and receiver isr worked. Now I have the following questions:

1- I used a program to send a packet to the DSP but only one character was received. if I type characters manually, ISR works fine and I get the characters. I noticed that the following code in the IDLE task caused the problem. my question: UART receive is a HWI and should be higher priority than the idle task, so why UART ISR skips interrupts?

Void idle0Fxn(Void)

{

      System_printf("I am idle ...\n");

}

2-

What flags do I need to clear inside the ISR. I am used to clear Flags in the IFR in the microcontroller world, but here I have system and host...what do I need to clear...if any?

Any help!?