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******************************************************************************/
/******************************************************************************
*
* @file xspi_eeprom_example.c
*
*
* This file contains a design example using the SPI driver (XSpi) and
* hardware device with a serial EEPROM device. The hardware which this
* example runs on must have a serial EEPROM (Microchip 25XX320 or 25XX160)
* for it to run. This example has been tested with the SPI EEPROM on the ML410
* platform for PPC processor.
*
* @note
*
* None.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver Who Date Changes
* ----- ---- -------- -----------------------------------------------
* 1.00b jhl 02/27/01 First release
* 1.00c jhl 08/15/03 Fixed bugs (local instances and large buffers are now
* moved to globals)
* 1.11a sv 9/10/07 Minor changes to comply to Doxygen and coding guidelines
* 3.00a ktn 10/28/09 Converted all register accesses to 32 bit access.
* Updated to use the HAL APIs/macros. Replaced call to
* XSpi_Initialize API with XSpi_LookupConfig and
* XSpi_CfgInitialize.
*</pre>
*
******************************************************************************/
/***************************** Include Files *********************************/
#include "xparameters.h" /* EDK generated parameters */
#include "xspi.h" /* SPI device driver */
#include "xintc.h" /* Interrupt controller device driver */
#include "xil_exception.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 SPI_DEVICE_ID XPAR_SPI_0_DEVICE_ID
#define INTC_DEVICE_ID XPAR_INTC_0_DEVICE_ID
#define SPI_INTR_ID XPAR_INTC_0_SPI_0_VEC_ID
/*
* The following constants define the commands which may be sent to the EEPROM
* device.
*/
#define WRITE_STATUS_CMD 1
#define WRITE_CMD 2
#define READ_CMD 3
#define WRITE_DISABLE_CMD 4
#define READ_STATUS_CMD 5
#define WRITE_ENABLE_CMD 6
/*
* The following constants define the offsets within a EepromBuffer data
* type for each kind of data. Note that the read data offset is not the
* same as the write data because the SPI driver is designed to allow full
* duplex transfers such that the number of bytes received is the number
* sent and received.
*/
#define COMMAND_OFFSET 0 /* EEPROM instruction */
#define ADDRESS_MSB_OFFSET 1 /* MSB of address to read or write */
#define ADDRESS_LSB_OFFSET 2 /* LSB of address to read or write */
#define DATA_OFFSET 3
#define WRITE_DATA_OFFSET 3 /* Start of data to write to the EEPROM */
#define READ_DATA_OFFSET 6 /* Start of data read from the EEPROM */
/*
* The following constants specify the extra bytes which are sent to the
* EEPROM on the SPI interface, that are not data, but control information
* which includes the command and address
*/
#define OVERHEAD_SIZE 3
/*
* The following constants specify the page size and number of pages for the
* EEPROM. The page size specifies a max number of bytes that can be written
* to the EEPROM with a single transfer using the SPI driver.
*/
#define PAGE_SIZE 16
#define PAGE_COUNT 128
/*
* The following constants specify the max amount of data and the size of the
* the buffer required to hold the data and overhead to transfer the data to
* and from the EEPROM.
*/
#define MAX_DATA PAGE_COUNT * PAGE_SIZE
#define BUFFER_SIZE MAX_DATA + READ_DATA_OFFSET
/*
* The following constant defines the slave select signal that is used to
* to select the EEPROM device on the SPI bus, this signal is typically
* connected to the chip select of the device
*/
#define SEEPROM_SPI_SELECT 0x01
/**************************** Type Definitions *******************************/
/*
* The following data type is used to send and receive data to the serial
* EEPROM device connected to the SPI interface. It is an array of bytes
* rather than a structure for portability avoiding packing issues. The
* application must setup the data to be written in this buffer and retrieve
* the data read from it.
*/
typedef u8 EepromBuffer[BUFFER_SIZE];
/***************** Macros (Inline Functions) Definitions *********************/
/************************** Function Prototypes ******************************/
static int SetupInterruptSystem(XSpi *SpiPtr);
void SpiHandler(void *CallBackRef, u32 StatusEvent, unsigned int ByteCount);
void EepromRead(XSpi *SpiPtr, u16 Address, int ByteCount, EepromBuffer Buffer);
void EepromWrite(XSpi *SpiPtr, u16 Address, u8 ByteCount, EepromBuffer Buffer);
/************************** Variable Definitions *****************************/
/*
* The instances to support the device drivers are global such that the
* are initialized to zero each time the program runs. They could be local
* but should at least be static so they are zeroed.
*/
XIntc InterruptController;
XSpi Spi;
/*
* The following variables are shared between non-interrupt processing and
* interrupt processing such that they must be global.
*/
volatile int TransferInProgress;
/*
* The following variable tracks any errors that occur during interrupt
* processing
*/
int Error;
/*
* The following variable allows a test value to be added to the values that
* are written to the EEPROM such that unique values can be generated to
* guarantee the writes to the EEPROM were successful
*/
int Test;
/*
* The following variables are used to read and write to the eeprom and they
* are global to avoid having large buffers on the stack
*/
EepromBuffer ReadBuffer;
EepromBuffer WriteBuffer;
/*****************************************************************************
*
* The purpose of this function is to illustrate how to use the XSpi
* device driver. This test writes and reads data from a Microchip serial EEPROM.
* This part must be present in the hardware to use this example.
*
* @param None
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note
*
* This function calls functions which contain loops that may be infinite
* if interrupts are not working such that it may not return. If the device
* slave select is not correct and the device is not responding on bus it will
* read a status of 0xFF for the status register as the bus is pulled up.
*
*****************************************************************************/
int main()
{
int Status;
u8 *BufferPtr;
u8 UniqueValue;
int Count;
int Page;
XSpi_Config *ConfigPtr; /* Pointer to Configuration data */
/*
* Initialize the SPI driver so that it is ready to use.
*/
ConfigPtr = XSpi_LookupConfig(SPI_DEVICE_ID);
if (ConfigPtr == NULL) {
return XST_DEVICE_NOT_FOUND;
}
Status = XSpi_CfgInitialize(&Spi, ConfigPtr,
ConfigPtr->BaseAddress);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Connect the SPI driver to the interrupt subsystem such that
* interrupts can occur. This function is application specific.
*/
Status = SetupInterruptSystem(&Spi);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Setup the handler for the SPI that will be called from the interrupt
* context when an SPI status occurs, specify a pointer to the SPI
* driver instance as the callback reference so the handler is able to
* access the instance data
*/
XSpi_SetStatusHandler(&Spi, &Spi, (XSpi_StatusHandler)SpiHandler);
/*
* Set the SPI device as a master and in manual slave select mode such
* that the slave select signal does not toggle for every byte of a
* transfer, this must be done before the slave select is set
*/
Status = XSpi_SetOptions(&Spi, XSP_MASTER_OPTION |
XSP_MANUAL_SSELECT_OPTION);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Select the slave on the SPI bus, the EEPROM device so that it can be
* read and written using the SPI bus
*/
Status = XSpi_SetSlaveSelect(&Spi, SEEPROM_SPI_SELECT);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Start the SPI driver so that interrupts and the device are enabled
*/
XSpi_Start(&Spi);
/*
* Initialize the write buffer for a pattern to write to the EEPROM
* and the read buffer to zero so it can be verified after the read, the
* test value that is added to the unique value allows the value to be
* changed in a debug environment to guarantee
*/
for (UniqueValue = 10, Count = 0; Count < MAX_DATA;
Count++, UniqueValue++) {
WriteBuffer[WRITE_DATA_OFFSET + Count] =
(u8)(UniqueValue + Test);
ReadBuffer[READ_DATA_OFFSET + Count] = 0;
}
/*
* Write the data in the write buffer to the serial EEPROM a page at a
* time
*/
for (Page = 0; Page < PAGE_COUNT; Page++) {
EepromWrite(&Spi, Page * PAGE_SIZE, PAGE_SIZE,
&WriteBuffer[Page * PAGE_SIZE]);
}
/*
* Read the contents of the entire EEPROM from address 0, since this
* function reads the entire EEPROM it will take some amount of time to
* complete
*/
EepromRead(&Spi, 0, MAX_DATA, ReadBuffer);
/*
* Setup a pointer to the start of the data that was read into the read
* buffer and verify the data read is the data that was written
*/
BufferPtr = &ReadBuffer[READ_DATA_OFFSET];
for (UniqueValue = 10, Count = 0; Count < MAX_DATA;
Count++, UniqueValue++) {
if (BufferPtr[Count] != (u8)(UniqueValue + Test)) {
return XST_FAILURE;
}
}
return XST_SUCCESS;
}
/******************************************************************************
*
* This function is the handler which performs processing for the SPI driver.
* It is called from an interrupt context such that the amount of processing
* performed should be minimized. It is called when a transfer of SPI data
* completes or an error occurs.
*
* This handler provides an example of how to handle SPI interrupts
* but is application specific.
*
*
* @param CallBackRef is a reference passed to the handler.
* @param StatusEvent is the status of the SPI .
* @param ByteCount is the number of bytes transferred.
*
* @return None
*
* @note None.
*
******************************************************************************/
void SpiHandler(void *CallBackRef, u32 StatusEvent, unsigned int ByteCount)
{
/*
* Indicate the transfer on the SPI bus is no longer in progress
* regardless of the status event
*/
TransferInProgress = FALSE;
/*
* If the event was not transfer done, then track it as an error
*/
if (StatusEvent != XST_SPI_TRANSFER_DONE) {
Error++;
}
}
/******************************************************************************
*
* This function reads from the Microchip serial EEPROM connected to the
* SPI interface.
*
* @param SpiPtr is a pointer to the SPI driver component to use.
* @param Address contains the address to read data from in the EEPROM.
* @param ByteCount contains the number of bytes to read.
* @param Buffer is a buffer to read the data into.
*
* @return None.
*
* @note None.
*
******************************************************************************/
void EepromRead(XSpi *SpiPtr, u16 Address, int ByteCount, EepromBuffer Buffer)
{
/*
* Setup the write command with the specified address and data for the
* EEPROM
*/
Buffer[COMMAND_OFFSET] = READ_CMD;
Buffer[ADDRESS_MSB_OFFSET] = (u8)((Address & 0xFF00) >> 8);
Buffer[ADDRESS_LSB_OFFSET] = (u8)(Address & 0x00FF);
/*
* Send the read command to the EEPROM to read the specified number
* of bytes from the EEPROM, send the read command and address and
* receive the specified number of bytes of data in the data buffer
*/
TransferInProgress = TRUE;
XSpi_Transfer(SpiPtr, Buffer, &Buffer[DATA_OFFSET],
ByteCount + OVERHEAD_SIZE);
/*
* Wait for the transfer on the SPI bus to be complete before proceeding
*/
while (TransferInProgress);
}
/******************************************************************************
*
*
* This function writes to the Microchip serial EEPROM connected to the
* SPI interface. This function is not designed to be a driver to handle all
* the conditions of the EEPROM device. The EEPROM contains a 32 byte write
* buffer which can be filled and then a write is automatically performed by
* the device. All the data put into the buffer must be in the same page of
* the device with page boundaries being on 32 byte boundaries.
*
* @param SpiPtr is a pointer to the SPI driver component to use.
* @param Address contains the address to write data to in the EEPROM.
* @param ByteCount contains the number of bytes to write.
* @param Buffer is a buffer of data to write from.
*
* @return None.
*
* @note None.
*
******************************************************************************/
void EepromWrite(XSpi *SpiPtr, u16 Address, u8 ByteCount, EepromBuffer Buffer)
{
u8 WriteEnableCmd = { WRITE_ENABLE_CMD };
u8 ReadStatusCmd[] = { READ_STATUS_CMD, 0 }; /* must send 2 bytes */
u8 EepromStatus[2];
int DelayCount = 0;
/*
* Send the write enable command to the SEEPOM so that it can be
* written to, this needs to be sent as a seperate transfer before
* the write
*/
TransferInProgress = TRUE;
XSpi_Transfer(SpiPtr, &WriteEnableCmd, NULL, sizeof(WriteEnableCmd));
/*
* Wait for the transfer on the SPI bus to be complete before proceeding
*/
while (TransferInProgress);
/*
* Setup the write command with the specified address and data for the
* EEPROM
*/
Buffer[COMMAND_OFFSET] = WRITE_CMD;
Buffer[ADDRESS_MSB_OFFSET] = (u8)((Address & 0xFF00) >> 8);
Buffer[ADDRESS_LSB_OFFSET] = (u8)(Address & 0x00FF);
/*
* Send the write command, address, and data to the EEPROM to be
* written, no receive buffer is specified since there is nothing to
* receive
*/
TransferInProgress = TRUE;
XSpi_Transfer(SpiPtr, Buffer, NULL, ByteCount + OVERHEAD_SIZE);
while (TransferInProgress);
/*
* Wait for a bit of time to allow the programming to occur as reading
* the status while programming causes it to fail because of noisy power
* on the board containing the EEPROM, this loop does not need to be
* very long but is longer to hopefully work for a faster processor
*/
while (DelayCount++ < 10000) {
}
/*
* Wait for the write command to the EEPROM to be completed, it takes
* some time for the data to be written
*/
while (1) {
/*
* Poll the status register of the device to determine when it
* completes by sending a read status command and receiving the
* status byte
*/
TransferInProgress = TRUE;
XSpi_Transfer(SpiPtr, ReadStatusCmd, EepromStatus,
sizeof(ReadStatusCmd));
/*
* Wait for the transfer on the SPI bus to be complete before
* proceeding
*/
while (TransferInProgress);
/*
* If the status indicates the write is done, the stop waiting,
* if a value of 0xFF in the status byte is read from the
* device and this loop never exits, the device slave select is
* possibly incorrect such that the device status is not being
* read
*/
if ((EepromStatus[1] & 0x03) == 0) {
break;
}
}
}
/****************************************************************************
*
*
* This function setups the interrupt system such that interrupts can occur
* for the SPI driver. This function is application specific since the actual
* system may or may not have an interrupt controller. The SPI device could
* be directly connected to a processor without an interrupt controller. The
* user should modify this function to fit the application.
*
* @param SpiPtr contains a pointer to the instance of the XSpi component
* which is going to be connected to the interrupt controller.
*
* @return XST_SUCCESS if successful else XST_FAILURE.
*
* @note None.
*
****************************************************************************/
static int SetupInterruptSystem(XSpi *SpiPtr)
{
int Status;
/*
* Initialize the interrupt controller driver so that
* it's ready to use, specify the device ID that is generated in
* xparameters.h
*/
Status = XIntc_Initialize(&InterruptController, INTC_DEVICE_ID);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Connect a device driver handler that will be called when an interrupt
* for the device occurs, the device driver handler performs the
* specific interrupt processing for the device
*/
Status = XIntc_Connect(&InterruptController,
SPI_INTR_ID,
(XInterruptHandler)XSpi_InterruptHandler,
(void *)SpiPtr);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Start the interrupt controller such that interrupts are enabled for
* all devices that cause interrupts, specific real mode so that
* the SPI can cause interrupts thru the interrupt controller.
*/
Status = XIntc_Start(&InterruptController, XIN_REAL_MODE);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Enable the interrupt for the Spi device
*/
XIntc_Enable(&InterruptController, SPI_INTR_ID);
/*
* Initialize the exception table
*/
Xil_ExceptionInit();
/*
* Register the interrupt controller handler with the exception table
*/
Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
(Xil_ExceptionHandler)XIntc_InterruptHandler,
&InterruptController);
/*
* Enable non-critical exceptions
*/
Xil_ExceptionEnable();
return XST_SUCCESS;
}