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/*****************************************************************************/
/**
* @file xspi_eeprom_polled_example.c
**
* This file contains a design example using the SPI driver (XSpiPs) in
* polled mode 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 EP4.5 ARM processor.
*
* @note
*
* None.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver Who Date Changes
* ----- ---- -------- -----------------------------------------------
* 1.00 sdm 03/09/10 First release
* 1.00 sdm 10/25/11 Updated the chip select to be used to second chip select
*
*</pre>
*
******************************************************************************/
/***************************** Include Files *********************************/
#include "xparameters.h" /* EDK generated parameters */
#include "xspips.h" /* SPI device driver */
#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 SPI_DEVICE_ID XPAR_XSPIPS_0_DEVICE_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 EEPROM_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 ******************************/
void EepromRead(XSpiPs *SpiPtr, u16 Address, int ByteCount,
EepromBuffer Buffer);
void EepromWrite(XSpiPs *SpiPtr, u16 Address, u8 ByteCount,
EepromBuffer Buffer);
int SpiPsEepromPolledExample(XSpiPs *SpiInstancePtr, u16 SpiDeviceId);
/************************** 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.
*/
static XSpiPs SpiInstance;
/*
* 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;
/*****************************************************************************/
/**
*
* Main function to call the Spi Eeprom example.
*
* @param None
*
* @return XST_SUCCESS if successful, otherwise XST_FAILURE.
*
* @note None
*
******************************************************************************/
int main(void)
{
int Status;
xil_printf("SPI EEPROM Polled Mode Example Test \r\n");
/*
* Run the Spi Interrupt example.
*/
Status = SpiPsEepromPolledExample(&SpiInstance, SPI_DEVICE_ID);
if (Status != XST_SUCCESS) {
xil_printf("SPI EEPROM Polled Mode Example Test Failed\r\n");
return XST_FAILURE;
}
xil_printf("Successfully ran SPI EEPROM Polled Mode Example Test\r\n");
return XST_SUCCESS;
}
/*****************************************************************************
*
* The purpose of this function is to illustrate how to use the XSpiPs
* device driver in polled mode. This test writes and reads data from a
* serial EEPROM. The serial EEPROM part must be present in the hardware
* to use this example.
*
* @param SpiInstancePtr is a pointer to the Spi Instance.
* @param SpiDeviceId is the Device Id of Spi.
*
* @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 SpiPsEepromPolledExample(XSpiPs *SpiInstancePtr, u16 SpiDeviceId)
{
int Status;
u8 *BufferPtr;
u8 UniqueValue;
int Count;
int Page;
XSpiPs_Config *SpiConfig;
/*
* Initialize the SPI driver so that it's ready to use
*/
SpiConfig = XSpiPs_LookupConfig(SpiDeviceId);
if (NULL == SpiConfig) {
return XST_FAILURE;
}
Status = XSpiPs_CfgInitialize(SpiInstancePtr, SpiConfig,
SpiConfig->BaseAddress);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Perform a self-test to check hardware build
*/
Status = XSpiPs_SelfTest(SpiInstancePtr);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Set the Spi device as a master. External loopback is required.
*/
XSpiPs_SetOptions(SpiInstancePtr, XSPIPS_MASTER_OPTION |
XSPIPS_FORCE_SSELECT_OPTION);
XSpiPs_SetClkPrescaler(SpiInstancePtr, XSPIPS_CLK_PRESCALE_64);
/*
* 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 = 13, Count = 0; Count < MAX_DATA;
Count++, UniqueValue++) {
WriteBuffer[WRITE_DATA_OFFSET + Count] =
(u8)(UniqueValue + Test);
ReadBuffer[READ_DATA_OFFSET + Count] = 0xA5;
}
/*
* Assert the EEPROM chip select
*/
XSpiPs_SetSlaveSelect(SpiInstancePtr, EEPROM_SPI_SELECT);
/*
* Write the data in the write buffer to the serial EEPROM a page at a
* time, read the data back from the EEPROM and verify it
*/
UniqueValue = 13;
for (Page = 0; Page < PAGE_COUNT; Page++) {
EepromWrite(SpiInstancePtr, Page * PAGE_SIZE, PAGE_SIZE,
&WriteBuffer[Page * PAGE_SIZE]);
EepromRead(SpiInstancePtr, Page * PAGE_SIZE, PAGE_SIZE,
ReadBuffer);
BufferPtr = &ReadBuffer[READ_DATA_OFFSET];
for (Count = 0; Count < PAGE_SIZE; Count++, UniqueValue++) {
if (BufferPtr[Count] != (u8)(UniqueValue + Test)) {
return XST_FAILURE;
}
}
}
return XST_SUCCESS;
}
/******************************************************************************
*
* This function reads from the 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(XSpiPs *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
*/
XSpiPs_PolledTransfer(SpiPtr, Buffer, &Buffer[DATA_OFFSET],
ByteCount + OVERHEAD_SIZE);
}
/******************************************************************************
*
*
* This function writes to the 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 instance 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(XSpiPs *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
*/
XSpiPs_PolledTransfer(SpiPtr, &WriteEnableCmd, NULL,
sizeof(WriteEnableCmd));
/*
* 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
*/
XSpiPs_PolledTransfer(SpiPtr, Buffer, NULL, ByteCount + OVERHEAD_SIZE);
/*
* 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
*/
XSpiPs_PolledTransfer(SpiPtr, ReadStatusCmd, EepromStatus,
sizeof(ReadStatusCmd));
/*
* If the status indicates the write is done, then 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;
}
}
}