//-----------------------------------------------------------------------------
// F12x_SPI0_EEPROM_Polled_Mode.c
//-----------------------------------------------------------------------------
// Copyright 2006 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program accesses a SPI EEPROM using polled mode access. The 'F12x 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 'F12x MCU are shown here:
// 
// P0.0 - UART TXD   (digital output, push-pull)
// P0.1 - UART RXD   (digital input, open-drain)
// P0.2 - SPI SCK    (digital output, push-pull)
// P0.3 - SPI MISO   (digital input, open-drain)
// P0.4 - SPI MOSI   (digital output, push-pull)
// P0.5 - SPI NSS    (digital output, push-pull)
// P1.6 - LED        (digital output, push-pull)
//
//
// How To Test:
//
// Method1:
// 1) Download the code to a 'F12x 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 'F12x device that is connected as above, and 
//    also connected to a RS232 transceiver.
// 2) Connect a straight serial cable from the RS232 transceiver to a PC.
// 3) On the PC, open HyperTerminal (or any other terminal program) and connect
//    to the COM port at <BAUDRATE> and 8-N-1.
// 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:         C8051F12x
// Tool chain:     Keil C51 7.50 / Keil EVAL C51
// Command Line:   None
//
// Release 1.0
//    -Initial Revision (PKC)
//    -31 MAY 2006
//

//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------
#include <C8051F120.h>                 // SFR declarations
#include <stdio.h>                     // printf is declared here

//-----------------------------------------------------------------------------
// 16-bit SFR Definitions for the 'F12x
//-----------------------------------------------------------------------------
sfr16 TMR2     = 0xCC;                 // Timer2 low and high bytes together

//-----------------------------------------------------------------------------
// User-defined types, structures, unions etc
//-----------------------------------------------------------------------------
#ifndef BYTE
#define BYTE unsigned char
#endif

#ifndef UINT
#define UINT unsigned int
#endif

//-----------------------------------------------------------------------------
// Global Constants
//-----------------------------------------------------------------------------
#define BAUDRATE           115200      // Baud rate of UART in bps
#define SYSCLK             24500000    // 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 = P1^6;                       // LED='1' means ON

//-----------------------------------------------------------------------------
// Function Prototypes
//-----------------------------------------------------------------------------
// The following functions DO NOT save and restore SFRPAGE:
void Reset_Sources_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);

// The following functions save and restore SFRPAGE:
void Delay_us (BYTE time_us);
void Delay_ms (BYTE time_ms);
void EEPROM_Write (UINT address, BYTE value);
BYTE EEPROM_Read (UINT address);

//-----------------------------------------------------------------------------
// main() Routine
//-----------------------------------------------------------------------------
void main (void)
{
   UINT  address;                      // EEPROM address
   BYTE  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 = UART0_PAGE;               // Set to page0 for printf via UART0
                                       // LED on P1.6 is on all pages.
   
   // 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, (UINT)test_byte);
         LED = ~LED;
      }
      else
         printf ("%02x ", (UINT)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, (UINT)test_byte);
         LED = ~LED;
      }
      else
         printf ("%02x ", (UINT)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, (UINT)test_byte);
         LED = ~LED;
      }
      else
         printf ("%02x ", (UINT)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, (UINT)test_byte);
         LED = ~LED;
      }
      else
         printf ("%02x ", (UINT)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 Reset_Sources_Init (void)
{
   WDTCN     = 0xDE;
   WDTCN     = 0xAD;
}

//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function initializes the system clock to use the internal oscillator
// at 24.5 MHz.
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
   SFRPAGE   = CONFIG_PAGE;
   OSCICN    = 0x83;
}

//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function configures the crossbar and GPIO ports.
//
// P0.0  -  TX0 (UART0), Push-Pull,  Digital
// P0.1  -  RX0 (UART0), Open-Drain, Digital
// P0.2  -  SCK  (SPI0), Push-Pull,  Digital
// P0.3  -  MISO (SPI0), Open-Drain, Digital
// P0.4  -  MOSI (SPI0), Push-Pull,  Digital
// P0.5  -  NSS  (SPI0), Push-Pull,  Digital
// P0.6  -  Unassigned,  Open-Drain, Digital
// P0.7  -  Unassigned,  Open-Drain, Digital

// P1.0  -  Unassigned,  Open-Drain, Digital
// P1.1  -  Unassigned,  Open-Drain, Digital
// P1.2  -  Unassigned,  Open-Drain, Digital
// P1.3  -  Unassigned,  Open-Drain, Digital
// P1.4  -  Unassigned,  Open-Drain, Digital
// P1.5  -  Unassigned,  Open-Drain, Digital
// P1.6  -  Unassigned,  Push-Pull,  Digital (LED D3 on Target Board)
// P1.7  -  Unassigned,  Open-Drain, Digital

// P2.0  -  Unassigned,  Open-Drain, Digital
// P2.1  -  Unassigned,  Open-Drain, Digital
// P2.2  -  Unassigned,  Open-Drain, Digital
// P2.3  -  Unassigned,  Open-Drain, Digital
// P2.4  -  Unassigned,  Open-Drain, Digital
// P2.5  -  Unassigned,  Open-Drain, Digital
// P2.6  -  Unassigned,  Open-Drain, Digital
// P2.7  -  Unassigned,  Open-Drain, Digital