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******************************************************************************/
/****************************************************************************/
/**
*
* @file xcanps_polled_example.c
*
* Contains an example of how to use the XCanPs driver directly.
* This example shows the using the driver/device in polled mode.
*
* @note
*
* None.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver Who Date Changes
* ----- ----- -------- -----------------------------------------------
* 1.00a xd/sv 01/12/10 First release
* 2.1 adk 23/08/14 Fixed CR:798792 Peripheral test for CANPS IP in
* SDK claims a 40kbps baud rate but it's not.
* </pre>
*
******************************************************************************/
/***************************** Include Files *********************************/
#include "xcanps.h"
#include "xparameters.h"
#include "xil_printf.h"
/************************** Constant Definitions *****************************/
/*
* The following constants map to the XPAR parameters created in the
* xparameters.h file. They are defined here such that a user can easily
* change all the needed parameters in one place.
*/
#define CAN_DEVICE_ID XPAR_XCANPS_0_DEVICE_ID
/*
* Maximum CAN frame length in words.
*/
#define XCANPS_MAX_FRAME_SIZE_IN_WORDS (XCANPS_MAX_FRAME_SIZE / sizeof(u32))
#define FRAME_DATA_LENGTH 8 /* Frame Data field length */
/*
* Message Id Constant.
*/
#define TEST_MESSAGE_ID 2000
/*
* The Baud Rate Prescaler Register (BRPR) and Bit Timing Register (BTR)
* are setup such that CAN baud rate equals 40Kbps, assuming that the
* the CAN clock is 24MHz. The user needs to modify these values based on
* the desired baud rate and the CAN clock frequency. For more information
* see the CAN 2.0A, CAN 2.0B, ISO 11898-1 specifications.
*/
/*
* Timing parameters to be set in the Bit Timing Register (BTR).
* These values are for a 40 Kbps baudrate assuming the CAN input clock
frequency
* is 24 MHz.
*/
#define TEST_BTR_SYNCJUMPWIDTH 3
#define TEST_BTR_SECOND_TIMESEGMENT 2
#define TEST_BTR_FIRST_TIMESEGMENT 15
/*
* The Baud rate Prescalar value in the Baud Rate Prescaler Register (BRPR)
* needs to be set based on the input clock frequency to the CAN core and
* the desired CAN baud rate.
* This value is for a 40 Kbps baudrate assuming the CAN input clock frequency
* is 24 MHz.
*/
#define TEST_BRPR_BAUD_PRESCALAR 29
/**************************** Type Definitions *******************************/
/***************** Macros (Inline Functions) Definitions *********************/
/************************** Function Prototypes ******************************/
int CanPsPolledExample(u16 DeviceId);
static int SendFrame(XCanPs *InstancePtr);
static int RecvFrame(XCanPs *InstancePtr);
/************************** Variable Definitions *****************************/
/*
* Buffers to hold frames to send and receive. These are declared as global so
* that they are not on the stack.
* These buffers need to be 32-bit aligned
*/
static u32 TxFrame[XCANPS_MAX_FRAME_SIZE_IN_WORDS];
static u32 RxFrame[XCANPS_MAX_FRAME_SIZE_IN_WORDS];
/* Driver instance */
static XCanPs Can;
/****************************************************************************/
/**
*
* This function is the main function of the Can polled example.
*
* @param None
*
* @return
* - XST_SUCCESS if the example has completed successfully.
* - XST_FAILURE if the example has failed.
*
* @note None
*
*****************************************************************************/
#ifndef TESTAPP_GEN
int main()
{
int Status;
xil_printf("CAN Polled Mode Example Test \r\n");
/*
* Run the Can Polled example, specify the Device ID that is generated
* in xparameters.h .
*/
Status = CanPsPolledExample(CAN_DEVICE_ID);
if (Status != XST_SUCCESS) {
xil_printf("CAN Polled Mode Example Test Failed\r\n");
return XST_FAILURE;
}
xil_printf("Successfully ran CAN Polled Mode Example Test\r\n");
return XST_SUCCESS;
}
#endif
/*****************************************************************************/
/**
*
* The entry point for showing the XCanPs driver in polled mode. The example
* configures the device for internal loop back mode, then sends a Can
* frame, receives the same Can frame, and verifies the frame contents.
*
* @param DeviceId is the XPAR_<CANPS_instance>_DEVICE_ID value from
* xparameters.h
*
* @return XST_SUCCESS if successful, otherwise driver-specific error code.
*
* @note
*
* If the device is not working correctly, this function may enter an infinite
* loop and will never return to the caller.
*
******************************************************************************/
int CanPsPolledExample(u16 DeviceId)
{
int Status;
XCanPs *CanInstPtr = &Can;
XCanPs_Config *ConfigPtr;
/*
* Initialize the Can device.
*/
ConfigPtr = XCanPs_LookupConfig(DeviceId);
if (CanInstPtr == NULL) {
return XST_FAILURE;
}
Status = XCanPs_CfgInitialize(CanInstPtr,
ConfigPtr,
ConfigPtr->BaseAddr);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Run self-test on the device, which verifies basic sanity of the
* device and the driver.
*/
Status = XCanPs_SelfTest(CanInstPtr);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Enter Configuration Mode so we can setup Baud Rate Prescaler
* Register (BRPR) and Bit Timing Register (BTR).
*/
XCanPs_EnterMode(CanInstPtr, XCANPS_MODE_CONFIG);
while(XCanPs_GetMode(CanInstPtr) != XCANPS_MODE_CONFIG);
/*
* Setup Baud Rate Prescaler Register (BRPR) and
* Bit Timing Register (BTR).
*/
XCanPs_SetBaudRatePrescaler(CanInstPtr, TEST_BRPR_BAUD_PRESCALAR);
XCanPs_SetBitTiming(CanInstPtr, TEST_BTR_SYNCJUMPWIDTH,
TEST_BTR_SECOND_TIMESEGMENT,
TEST_BTR_FIRST_TIMESEGMENT);
/*
* Enter Loop Back Mode.
*/
XCanPs_EnterMode(CanInstPtr, XCANPS_MODE_LOOPBACK);
while(XCanPs_GetMode(CanInstPtr) != XCANPS_MODE_LOOPBACK);
/*
* Send a frame, receive the frame via the loop back and verify its
* contents.
*/
Status = SendFrame(CanInstPtr);
if (Status != XST_SUCCESS) {
return Status;
}
Status = RecvFrame(CanInstPtr);
return Status;
}
/*****************************************************************************/
/**
*
* Send a CAN frame.
*
* @param InstancePtr is a pointer to the driver instance
*
* @return XST_SUCCESS if successful, a driver-specific return code if not.
*
* @note
*
* This function waits until TX FIFO has room for at least one frame before
* sending a frame. So this function may block if the hardware is not built
* correctly.
*
******************************************************************************/
static int SendFrame(XCanPs *InstancePtr)
{
u8 *FramePtr;
int Index;
int Status;
/*
* Create correct values for Identifier and Data Length Code Register.
*/
TxFrame[0] = (u32)XCanPs_CreateIdValue((u32)TEST_MESSAGE_ID, 0, 0, 0, 0);
TxFrame[1] = (u32)XCanPs_CreateDlcValue((u32)FRAME_DATA_LENGTH);
/*
* Now fill in the data field with known values so we can verify them
* on receive.
*/
FramePtr = (u8 *)(&TxFrame[2]);
for (Index = 0; Index < FRAME_DATA_LENGTH; Index++) {
*FramePtr++ = (u8)Index;
}
/*
* Wait until TX FIFO has room.
*/
while (XCanPs_IsTxFifoFull(InstancePtr) == TRUE);
/*
* Now send the frame.
*
* Another way to send a frame is keep calling XCanPs_Send() until it
* returns XST_SUCCESS. No check on if TX FIFO is full is needed anymore
* in that case.
*/
Status = XCanPs_Send(InstancePtr, TxFrame);
return Status;
}
/*****************************************************************************/
/**
*
* This function receives a frame and verifies its contents.
*
* @param InstancePtr is a pointer to the driver instance.
*
* @return XST_SUCCESS if successful, a driver-specific return code if not.
*
* @note
*
* This function waits until RX FIFO becomes not empty before reading a frame
* from it. So this function may block if the hardware is not built
* correctly.
*
******************************************************************************/
static int RecvFrame(XCanPs *InstancePtr)
{
u8 *FramePtr;
int Status;
int Index;
/*
* Wait until a frame is received.
*/
while (XCanPs_IsRxEmpty(InstancePtr) == TRUE);
/*
* Receive a frame and verify its contents.
*/
Status = XCanPs_Recv(InstancePtr, RxFrame);
if (Status == XST_SUCCESS) {
/*
* Verify Identifier and Data Length Code.
*/
if (RxFrame[0] !=
(u32)XCanPs_CreateIdValue((u32)TEST_MESSAGE_ID, 0, 0, 0, 0))
return XST_LOOPBACK_ERROR;
if ((RxFrame[1] & ~XCANPS_DLCR_TIMESTAMP_MASK) != TxFrame[1])
return XST_LOOPBACK_ERROR;
/*
* Verify Data field contents.
*/
FramePtr = (u8 *)(&RxFrame[2]);
for (Index = 0; Index < FRAME_DATA_LENGTH; Index++) {
if (*FramePtr++ != (u8)Index) {
return XST_LOOPBACK_ERROR;
}
}
}
return Status;
}