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Debug went crazy

Jonathan100 (92)
Hi friends.
I built some simple i2c protocol driver code to work with Xilinx.
When I debug the code, something strange happens - the code run back and forth between 2 lines and never continue (And in debug it's always go sequentially).

Here is a code-snippet:

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	while(1){
		statug_reg = Xil_In32(IIC_IP_BaseAddr+SR_Address);
		if ((statug_reg>>1)&0x1){   // slv_addr detected
			printf("\n\rstep 1 - slv_addr detected\n\r");

			if ((((Xil_In32(IIC_IP_BaseAddr+SR_Address))>>3)&0x1) == 0){  //master writing to slave
				printf("\n\rstep 2 - master writing to slave\n\r");
				for(int i=0; i<recvLen;i++) {

					CheckFifoNotEmpty(IIC_IP_BaseAddr);
					data_in = Xil_In32(IIC_IP_BaseAddr+Rx_FIFO);
					*(rxDataBuffer+i) = data_in;
					printf("Read location %d in Rx_FIFO\n\r",i);
				}
				return 0;
			}
		}
	}


The debug goes back and forth lines 2 and 3.

Xil_In32 definition:

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*
* @brief    Performs an input operation for a memory location by
*           reading from the specified address and returning the 32 bit Value
*           read  from that address.
*
* @param	Addr: contains the address to perform the input operation
*
* @return	The 32 bit Value read from the specified input address.
*
******************************************************************************/
static INLINE u32 Xil_In32(UINTPTR Addr)
{
	return *(volatile u32 *) Addr;
}


I guess it is something to so with this function, but I can't figure out what.



Last edited on
salem c (3700)
Maybe Xil_In32 also needs to be declared as a volatile function.

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static volatile INLINE u32 Xil_In32(UINTPTR Addr)
{
	return *(volatile u32 *) Addr;
}



The same would be true for any other function which reads external hardware, and that hardware is capable of changing state without the program doing anything.

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