Silicon Labs给的例程不能成功写入SPI EEPRom -

//-----------------------------------------------------------------------------
// F500_SPI0_EEPROM_Polled_Mode.c
//-----------------------------------------------------------------------------
// Copyright 2008 Silicon Laboratories, Inc.
//
// Program Description:
//
// This program accesses a SPI EEPROM using polled mode access. The 'F500 MCU
// is configured in 4-wire Single Master Mode, and the EEPROM is the only
// slave device connected to the SPI bus. The read/write operations are
// tailored to access a Microchip 4 kB EEPROM 25LC320. The relevant hardware
// connections of the 'F500 MCU are shown here:
//
// P0.0 - SPI SCK (digital output, push-pull)
// P0.1 - SPI MISO (digital input, open-drain)
// P0.2 - SPI MOSI (digital output, push-pull)
// P0.3 - SPI NSS (digital output, push-pull)
// P0.4 - UART TXD (digital output, push-pull)
// P0.5 - UART RXD (digital input, open-drain)
// P1.3 - LED (digital output, push-pull)
//
//
// How To Test:
//
// Method1:
// 1) Download the code to a 'F500 device that is connected as above.
// 2) Run the code. The LED will blink fast during the write/read/verify
// operations.
// 3) If the verification passes, the LED will blink slowly. If it fails,
// the LED will be OFF.
//
// Method2 (optional):
// 1) Download code to a 'F500 device that is connected as above
// 2) Connect USB cable from the development board to a PC
// 3) On the PC, open HyperTerminal (or any other terminal program) and connect
// to the USB port (virtual com port) at <BAUDRATE>, 8 data bits, no parity,
// 1 stop bit, no flow control.
// 4) HyperTerminal will print the progress of the write/read operation, and in
// the end will print the test result as pass or fail. Additionally, if the
// verification passes, the LED will blink slowly. If it fails, the LED will
// be OFF.
//
//
// Target: C8051F500 (Side A of a C8051F500-TB)
// Tool chain: Keil C51 8.0 / Keil EVAL C51
// Command Line: None
//
// Release 1.0 / 06 MAR 2008 (GP)
// -Initial Revision
//
//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------
#include <compiler_defs.h>
#include <C8051F500_defs.h> // SFR declarations
#include <stdio.h> // printf is declared here
//-----------------------------------------------------------------------------
// Global Constants
//-----------------------------------------------------------------------------
#define BAUDRATE 115200 // Baud rate of UART in bps
#define SYSCLK 24000000 // Internal oscillator frequency in Hz
// Microchip 25AA320 Slave EEPROM Parameters
#define F_SCK_MAX 2000000 // Max SCK freq (Hz)
#define T_NSS_DISABLE_MIN 500 // Min NSS disable time (ns)
#define EEPROM_CAPACITY 4096 // EEPROM capacity (bytes)
// EEPROM Instruction Set
#define EEPROM_CMD_READ 0x03 // Read Command
#define EEPROM_CMD_WRITE 0x02 // Write Command
#define EEPROM_CMD_WRDI 0x04 // Reset Write Enable Latch Command
#define EEPROM_CMD_WREN 0x06 // Set Write Enable Latch Command
#define EEPROM_CMD_RDSR 0x05 // Read Status Register Command
#define EEPROM_CMD_WRSR 0x01 // Write Status Register Command
SBIT (LED, SFR_P1, 3); // LED==1 means ON
//-----------------------------------------------------------------------------
// Function Prototypes
//-----------------------------------------------------------------------------
void PCA0_Init (void);
void OSCILLATOR_Init (void);
void PORT_Init (void);
void TIMER2_Init (void);
void UART0_Init (void);
void SPI0_Init (void);
void Init_Device (void);
void Delay_us (U8 time_us);
void Delay_ms (U8 time_ms);
void EEPROM_Write (U16 address, U8 value);
U8 EEPROM_Read (U16 address);
//-----------------------------------------------------------------------------
// main() Routine
//-----------------------------------------------------------------------------
void main (void)
{
U16 address; // EEPROM address
U8 test_byte; // Used as a temporary variable
Init_Device (); // Initializes hardware peripherals
// The following code will test the EEPROM by performing write/read/verify
// operations. The first test will write 0xFFs to the EEPROM, and the
// second test will write the LSBs of the EEPROM addresses.
SFRPAGE = ACTIVE_PAGE; // Set for printf()
// Fill EEPROM with 0xFF's
LED = 1;
printf("Filling with 0xFF's...\n");
for (address = 0; address < EEPROM_CAPACITY; address++)
{
test_byte = 0xFF;
EEPROM_Write (address, test_byte);
// Print status to UART0
if ((address % 16) == 0)
{
printf ("\nWriting 0x%04x: %02x ", address, (U16)test_byte);
LED = !LED;
}
else
{
printf ("%02x ", (U16)test_byte);
}
}
// Verify EEPROM with 0xFF's
printf("\n\nVerifying 0xFF's...\n");
for (address = 0; address < EEPROM_CAPACITY; address++)
{
test_byte = EEPROM_Read (address);
// Print status to UART0
if ((address % 16) == 0)
{
printf ("\nVerifying 0x%04x: %02x ", address, (U16)test_byte);
LED = !LED;
}
else
{
printf ("%02x ", (U16)test_byte);
}
if (test_byte != 0xFF)
{
LED = 0;
printf ("Error at %u\n", address);
while (1); // Stop here on error (for debugging)
}
}
// Fill EEPROM with LSB of EEPROM addresses
printf("\n\nFilling with LSB of EEPROM addresses...\n");
for (address = 0; address < EEPROM_CAPACITY; address++)
{
test_byte = address & 0xFF;
EEPROM_Write (address, test_byte);
// Print status to UART0
if ((address % 16) == 0)
{
printf ("\nWriting 0x%04x: %02x ", address, (U16)test_byte);
LED = !LED;
}
else
{
printf ("%02x ", (U16)test_byte);
}
}
// Verify EEPROM with LSB of EEPROM addresses
printf("\n\nVerifying LSB of EEPROM addresses...\n");
for (address = 0; address < EEPROM_CAPACITY; address++)
{
test_byte = EEPROM_Read (address);
// print status to UART0
if ((address % 16) == 0)
{
printf ("\nVerifying 0x%04x: %02x ", address, (U16)test_byte);
LED = !LED;
}
else
{
printf ("%02x ", (U16)test_byte);
}
if (test_byte != (address & 0xFF))
{
LED = 0;
printf ("Error at %u\n", address);
while (1); // Stop here on error (for debugging)
}
}
printf ("\n\nVerification success!\n");
while (1) // Loop forever
{
LED = !LED; // Flash LED when done (all verified)
Delay_ms (200);
}
}
//-----------------------------------------------------------------------------
// Initialization Subroutines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// PCA0_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This function disables the watchdog timer.
//
//-----------------------------------------------------------------------------
void PCA0_Init (void)
{
U8 SFRPAGE_save = SFRPAGE;
SFRPAGE = ACTIVE_PAGE;
PCA0MD &= ~0x40;
SFRPAGE = SFRPAGE_save;
}
//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This function initializes the system clock to use the internal oscillator
// at 24 MHz.
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
U8 SFRPAGE_save = SFRPAGE;
SFRPAGE = CONFIG_PAGE;
OSCICN = 0x87;
SFRPAGE = SFRPAGE_save;
}
//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This function configures the crossbar and GPIO ports.
//
// P0.0 - SCK (SPI0), Push-Pull, Digital
// P0.1 - MISO (SPI0), Open-Drain, Digital
// P0.2 - MOSI (SPI0), Push-Pull, Digital
// P0.3 - NSS (SPI0), Push-Pull, Digital
// P0.4 - TX0 (UART0), Push-Pull, Digital
// P0.5 - RX0 (UART0), Open-Drain, Digital
//
// P1.3 - Skipped, Push-Pull, Digital (LED D2 on Target Board)
// P1.4 - Skipped, Open-Drain, Digital (Switch S2 on Target Board)
//
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
U8 SFRPAGE_save = SFRPAGE;
SFRPAGE = CONFIG_PAGE;
P0MDOUT = 0x1D; // Configure P0.0/2/3/4 to push-pull
P1MDOUT = 0x08; // Configure P1.3 to push-pull
P1SKIP = 0x18; // Skip P1.3 and P1.4 on the crossbar
XBR0 = 0x05; // Enable SPI and UART0 on crossbar
XBR2 = 0x40; // Enable crossbar
SFRPAGE = SFRPAGE_save;
}
//-----------------------------------------------------------------------------
// TIMER2_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Initializes Timer2 to be clocked by SYSCLK for use as a delay timer.
//
//-----------------------------------------------------------------------------
void TIMER2_Init (void)
{
// CKCON is available on all pages
CKCON |= 0x10;
}
//-----------------------------------------------------------------------------
// UART0_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configure the UART0 using Baudrate generator, for <BAUDRATE1> and 8-N-1.
//
//-----------------------------------------------------------------------------
void UART0_Init (void)
{
U8 SFRPAGE_save = SFRPAGE;
SFRPAGE = CONFIG_PAGE;
SCON0 = 0x10; // SCON0: 8-bit variable bit rate
// clear RI0 and TI0 bits
// Baud Rate = [BRG Clock / (65536 - (SBRLH0:SBRLL0))] x 1/2 x 1/Prescaler
#if ((SYSCLK / BAUDRATE / 2 / 0xFFFF) < 1)
SBRL0 = -(SYSCLK / BAUDRATE / 2);
SBCON0 |= 0x03; // Set prescaler to 1
#elif ((SYSCLK / BAUDRATE / 2 / 0xFFFF) < 4)
SBRL0 = -(SYSCLK / BAUDRATE / 2 / 4);
SBCON0 &= ~0x03;
SBCON0 |= 0x01; // Set prescaler to 4
#elif ((SYSCLK / BAUDRATE / 2 / 0xFFFF) < 12)
SBRL0 = -(SYSCLK / BAUDRATE / 2 / 12);
SBCON0 &= ~0x03; // Set prescaler to 12
#else
SBRL0 = -(SYSCLK / BAUDRATE / 2 / 48);
SBCON0 &= ~0x03;
SBCON0 |= 0x02; // Set prescaler to 48
#endif
SBCON0 |= 0x40; // Enable baud rate generator
TI0 = 1; // Indicate TX0 ready
SFRPAGE = SFRPAGE_save;
}
//-----------------------------------------------------------------------------
// SPI0_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configures SPI0 to use 4-wire Single-Master mode. The SPI timing is
// configured for Mode 0,0 (data centered on first edge of clock phase and
// SCK line low in idle state). The SPI clock is set to 1.75 MHz. The NSS pin
// is set to 1.
//
//-----------------------------------------------------------------------------
void SPI0_Init()
{
U8 SFRPAGE_save = SFRPAGE;
SFRPAGE = ACTIVE_PAGE;
SPI0CFG = 0x40; // Enable the SPI as a Master
// CKPHA = '0', CKPOL = '0'
SPI0CN = 0x0D; // 4-wire, single master mode
// SPI0 enable
// The equation for SPI0CKR is (SYSCLK/(2*F_SCK_MAX))-1, but this yields
// a SPI frequency that is slightly more than 2 MHz. But, 2 MHz is the max
// frequency spec of the EEPROM used here. So, the "-1" term is omitted
// in the following usage:
SPI0CKR = (SYSCLK / (2 * F_SCK_MAX));
SFRPAGE = SFRPAGE_save;
}
//-----------------------------------------------------------------------------
// Init_Device
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Calls all device initialization functions.
//
//-----------------------------------------------------------------------------
void Init_Device (void)
{
PCA0_Init ();
OSCILLATOR_Init ();
PORT_Init ();
TIMER2_Init ();
UART0_Init ();
SPI0_Init ();
}
//-----------------------------------------------------------------------------
// Support Subroutines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// Delay_us
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : 1. time_us - time delay in microseconds
// range: 1 to 255
//
// Creates a delay for the specified time (in microseconds) using TIMER2. The
// time tolerance is approximately +/-50 ns (1/SYSCLK + function call time).
//
//-----------------------------------------------------------------------------
void Delay_us (U8 time_us)
{
U8 SFRPAGE_save = SFRPAGE;
SFRPAGE = ACTIVE_PAGE;
TR2 = 0; // Stop timer
TF2H = 0; // Clear timer overflow flag
TMR2 = -((U16)(SYSCLK / 1000000) * (U16)(time_us));
TR2 = 1; // Start timer
while (!TF2H); // Wait till timer overflow occurs
TR2 = 0; // Stop timer
SFRPAGE = SFRPAGE_save;
}
//-----------------------------------------------------------------------------
// Delay_ms
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : 1. time_ms - time delay in milliseconds
// range: 1 to 255
//
// Creates a delay for the specified time (in milliseconds) using TIMER2. The
// time tolerance is approximately +/-50 ns (1/SYSCLK + function call time).
//
//-----------------------------------------------------------------------------
void Delay_ms (U8 time_ms)
{
U8 i;
while(time_ms--)
{
for(i = 0; i< 10; i++) // 10 * 100 microsecond delay
{
Delay_us (100);
}
}
}
//-----------------------------------------------------------------------------
// EEPROM_Write
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : 1. address - the destination EEPROM address.
// range: 0 to EEPROM_CAPACITY
// 2. value - the value to write.
// range: 0x00 to 0xFF
//
// Writes one byte to the specified address in the EEPROM. This function polls
// the EEPROM status register after the write operation, and returns only after
// the status register indicates that the write cycle is complete. This is to
// prevent from having to check the status register before a read operation.
//
//-----------------------------------------------------------------------------
void EEPROM_Write (U16 address, U8 value)
{
U8 SFRPAGE_save = SFRPAGE;
SFRPAGE = ACTIVE_PAGE;
// Writing a byte to the EEPROM is a five-step operation.
// Step1: Set the Write Enable Latch to 1
NSSMD0 = 0; // Step1.1: Activate Slave Select
SPI0DAT = EEPROM_CMD_WREN; // Step1.2: Send the WREN command
while (!SPIF); // Step1.3: Wait for end of transfer
SPIF = 0; // Step1.4: Clear the SPI intr. flag
NSSMD0 = 1; // Step1.5: Deactivate Slave Select
Delay_us (1); // Step1.6: Wait for at least
// T_NSS_DISABLE_MIN
// Step2: Send the WRITE command
NSSMD0 = 0;
SPI0DAT = EEPROM_CMD_WRITE;
while (!SPIF);
SPIF = 0;
// Step3: Send the EEPROM destination address (MSB first)
SPI0DAT = (U8)((address >> 8) & 0x00FF);
while (!SPIF);
SPIF = 0;
SPI0DAT = (U8)(address & 0x00FF);
while (!SPIF);
SPIF = 0;
// Step4: Send the value to write
SPI0DAT = value;
while (!SPIF);
SPIF = 0;
NSSMD0 = 1;
Delay_us (1);
// Step5: Poll on the Write In Progress (WIP) bit in Read Status Register
do
{
NSSMD0 = 0; // Activate Slave Select
SPI0DAT = EEPROM_CMD_RDSR; // Send the Read Status Register command
while (!SPIF); // Wait for the command to be sent out
SPIF = 0;
SPI0DAT = 0; // Dummy write to output serial clock
while (!SPIF); // Wait for the register to be read
SPIF = 0;
NSSMD0 = 1; // Deactivate Slave Select after read
Delay_us (1);
} while((SPI0DAT & 0x01) == 0x01);
SFRPAGE = SFRPAGE_save;
}
//-----------------------------------------------------------------------------
// EEPROM_Read
//-----------------------------------------------------------------------------
//
// Return Value : The value that was read from the EEPROM
// range: 0x00 to 0xFF
// Parameters : 1. address - the source EEPROM address.
// range: 0 to EEPROM_CAPACITY
//
// Reads one byte from the specified EEPROM address.
//
//-----------------------------------------------------------------------------
U8 EEPROM_Read (U16 address)
{
U8 spi_data;
U8 SFRPAGE_save = SFRPAGE;
SFRPAGE = ACTIVE_PAGE;
// Reading a byte from the EEPROM is a three-step operation.
// Step1: Send the READ command
NSSMD0 = 0; // Activate Slave Select
SPI0DAT = EEPROM_CMD_READ;
while (!SPIF);
SPIF = 0;
// Step2: Send the EEPROM source address (MSB first)
SPI0DAT = (U8)((address >> 8) & 0x00FF);
while (!SPIF);
SPIF = 0;
SPI0DAT = (U8)(address & 0x00FF);
while (!SPIF);
SPIF = 0;
// Step3: Read the value returned
SPI0DAT = 0; // Dummy write to output serial clock
while (!SPIF); // Wait for the value to be read
SPIF = 0;
NSSMD0 = 1; // Deactivate Slave Select
Delay_us (1);
spi_data = SPI0DAT; // Read data before restoring SFR page
SFRPAGE = SFRPAGE_save;
return spi_data;
}
#ifdef SDCC
// SDCC does not include a definition for putchar(), which is used in printf()
// and so it is defined here. The prototype does not need to be explicitly
// defined because it is provided in stdio.h
//-----------------------------------------------------------------------------
// putchar
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : character to send to UART
//
// This function outputs a character to the UART.
//-----------------------------------------------------------------------------
void putchar (char input)
{
if (output == '\n')
{
while (!TI0);
TI0 = 0;
SBUF0 = 0x0d;
}
while (!TI0);
TI0 = 0;
SBUF0 = output;
}
#endif
//-----------------------------------------------------------------------------
// End Of File
//-----------------------------------------------------------------------------

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