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  /*****************************************************************************/
  /**
  *
  * @file xcan_selftest.c
  * @addtogroup can_v3_2
  * @{
  *
  * This file contains a diagnostic self-test function for the XCan driver.
  *
  * Please see xcan.h for more information.
  *
  * <pre>
  * MODIFICATION HISTORY:
  *
  * Ver   Who  Date     Changes
  * ----- ---- -------- ------------------------------------------------------
  * 1.00a xd   04/12/05 First release
  * 1.10a mta  05/13/07 Updated to new coding style
  * 2.00a ktn  10/22/09 Updated to use the HAL APIs/macros.
  *		      The macros have been renamed to remove _m from the name.
  * </pre>
  *
  *****************************************************************************/
  
  /***************************** Include Files ********************************/
  
  #include "xstatus.h"
  #include "xcan.h"
  
  /************************** Constant Definitions ****************************/
  
  #define XCAN_MAX_FRAME_SIZE_IN_WORDS (XCAN_MAX_FRAME_SIZE / sizeof(u32))
  
  /**************************** Type Definitions ******************************/
  
  /***************** Macros (Inline Functions) Definitions ********************/
  
  /************************** Variable Definitions ****************************/
  
  /* Buffers to hold frames to send and receive. */
  static u32 TxFrame[XCAN_MAX_FRAME_SIZE_IN_WORDS];
  static u32 RxFrame[XCAN_MAX_FRAME_SIZE_IN_WORDS];
  
  /************************** Function Prototypes *****************************/
  
  /*****************************************************************************/
  /**
  *
  * This function runs a self-test on the CAN driver/device. The test resets
  * the device, sets up the Loop Back mode, sends a standard frame, receives the
  * frame, verifies the contents, and resets the device again.
  *
  * Note that this is a destructive test in that resets of the device are
  * performed. Refer to the device specification for the device status
  * after the reset operation.
  *
  *
  * @param	InstancePtr is a pointer to the XCan instance to be worked on.
  *
  * @return
  *		- XST_SUCCESS   if the self-test passed. i.e., the frame
  *		received via the internal loop back has the same contents as the
  * 		sent frame.
  * 		- XST_FAILURE   Otherwise.
  *
  * @note
  *
  * If the CAN device does not work properly, this function may enter an
  * infinite loop and will never return to the caller.
  * <br><br>
  * If XST_FAILURE is returned, the device is not reset so that the caller could
  * have a chance to check reason(s) causing the failure.
  *
  ******************************************************************************/
  int XCan_SelfTest(XCan *InstancePtr)
  {
  	u8 *FramePtr;
  	u32 Result;
  	u32 Index;
  
  	Xil_AssertNonvoid(InstancePtr != NULL);
  	Xil_AssertNonvoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
  
  	/* Reset device first */
  	XCan_Reset(InstancePtr);
  
  	/*
  	 * The device should enter Configuration Mode immediately after the
  	 * reset above is finished. Now check the mode and return error code if
  	 * it is not Configuration Mode.
  	 */
  	if (XCan_GetMode(InstancePtr) != XCAN_MODE_CONFIG) {
  		return XST_FAILURE;
  	}
  
  	/*
  	 * Setup Baud Rate Prescaler Register (BRPR) and Bit Timing Register
  	 * (BTR) such that CAN baud rate equals 40Kbps, given the CAN clock
  	 * equal to 24MHz.
  	 */
  	XCan_SetBaudRatePrescaler(InstancePtr, 29);
  	XCan_SetBitTiming(InstancePtr, 3, 2, 15);
  
  	/* Enter loopback mode  */
  	XCan_EnterMode(InstancePtr, XCAN_MODE_LOOPBACK);
  	while (XCan_GetMode(InstancePtr) != XCAN_MODE_LOOPBACK);
  
  	/*
  	 * Create a frame to send with known values so we can verify them
  	 * on receive.
  	 */
  	TxFrame[0] = XCan_CreateIdValue(2650, 0, 0, 0, 0);
  	TxFrame[1] = XCan_CreateDlcValue(8);
  	FramePtr = (u8 *) (&TxFrame[2]);
  	for (Index = 0; Index < 8; Index++) {
  		*FramePtr++ = (u8) Index;
  	}
  
  	/* Send the frame. */
  	Result = XCan_Send(InstancePtr, TxFrame);
  	if (Result != XST_SUCCESS) {
  		return XST_FAILURE;
  	}
  
  	/* Wait until the frame arrives RX FIFO via internal loop back */
  	while (XCan_IsRxEmpty(InstancePtr) == TRUE);
  
  	/* Receive the frame */
  	Result = XCan_Recv(InstancePtr, RxFrame);
  	if (Result != XST_SUCCESS) {
  		return XST_FAILURE;
  	}
  
  	/* Compare received frame with sent frame */
  	for (Index = 0; Index < XCAN_MAX_FRAME_SIZE_IN_WORDS; Index++) {
  		if (RxFrame[Index] != TxFrame[Index]) {
  			return XST_FAILURE;
  		}
  	}
  
  	/* Reset device again before return to the caller */
  	XCan_Reset(InstancePtr);
  
  	return XST_SUCCESS;
  }
  
  
  /** @} */
  