f411_vr_sstflash.c

用c8051f410和FLASH（SPI接口）实现的数字录音机。

   NSSMD0 = 0;                         // enable the flash

   // send the read instruction
   SPI0DAT = READ;                     // load the XMIT register
   while (TXBMT != 1)                  // wait until the command is moved into
   {                                   // the XMIT buffer
   }
   SPI0DAT = temp_addr.UByte[1];       // load the high byte of the address
   while (TXBMT != 1)                  // wait until the data is moved into
   {                                   // the XMIT buffer
   }
   SPI0DAT = temp_addr.UByte[2];       // load the middle byte of the address
   while (TXBMT != 1)                  // wait until the data is moved into
   {                                   // the XMIT buffer
   }
   SPI0DAT = temp_addr.UByte[3];       // load the low byte of the address
   while (TXBMT != 1)                  // wait until the data is moved into
   {                                   // the XMIT buffer
   }
   SPI0DAT = 0xFF;                     // load junk data in order to receive
                                       // data from the flash
   while (TXBMT != 1)                  // wait until the junk data is moved
   {                                   // into the XMIT buffer
   }
   SPIF = 0;
   while (SPIF != 1)                   // wait until the read data is received
   {
   }
   SPIF = 0;

   NSSMD0 = 1;                         // disable the flash

   return SPI0DAT;
}

//-----------------------------------------------------------------------------
// Erase_MEM
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// Erase all data from the SST flash memory.
//
void Erase_MEM (void)
{
   unsigned char mem_status = 0x01;

   NSSMD0 = 0;                         // enable the flash

   // send the write enable command
   SPI0DAT = WREN;                     // load the XMIT register
   while (TXBMT != 1)                  // wait until the command is moved into
   {                                   // the XMIT buffer
   }
   SPIF = 0;
   while (SPIF != 1)                   // wait until the command reaches the
   {                                   // flash
   }
   SPIF = 0;

   NSSMD0 = 1;                         // allow the WREN to execute

   NSSMD0 = 0;                         // enable the flash

   // send the chip erase instruction
   SPI0DAT = CERASE;                   // load the XMIT register
   while (TXBMT != 1)                  // wait until the command is moved into
   {                                   // the XMIT buffer
   }
   SPIF = 0;
   while (SPIF != 1)                   // wait until the command reaches the
   {                                   // flash
   }
   SPIF = 0;

   NSSMD0 = 1;                         // allow the erase to execute

   // poll on the busy bit in the flash until the erase operation is complete
   NSSMD0 = 0;                         // enable the flash
   SPI0DAT = RDSR;                     // send the read status register command
   while (TXBMT != 1)                  // wait until the SPI can accept more
   {                                   // data
   }
   while (mem_status == 0x01)
   {
      SPI0DAT = 0xFF;                  // send junk in order to receive data
      while (TXBMT != 1)               // wait until the junk data is moved
      {                                // into the XMIT buffer
      }
      SPIF = 0;
      while (SPIF != 1)                // wait until the read data is received
      {
      }
      SPIF = 0;
      mem_status = SPI0DAT & 0x01;     // check the BUSY bit
   }

   NSSMD0 = 1;                         // disable the flash
}

//-----------------------------------------------------------------------------
// Read_MEM_Init
//-----------------------------------------------------------------------------
//
// Return Value :
//   1)  char data_byte - the data byte read from memory
//                      range is positive range of character: 0 to 255
// Parameters   :
//   1)  long address - address in the 512 kB external SST Flash
//                      range is postive values up to 2^19: 0 to 524287,
//                           or, 0 to 0x7FFFF
//
// Read one byte of data from a 24-bit address in the SST Flash Memory using
// the SPI.  This function is called by Recording_Search in F411_VR.c
// and is a duplicate of Read_MEM to avoid a warning by the compiler.
//
unsigned char Read_MEM_Init (unsigned long address)
{
   ADDRESS temp_addr;
   temp_addr.ULong = address;

   NSSMD0 = 0;                         // enable the flash

   // send the read instruction
   SPI0DAT = READ;                     // load the XMIT register
   while (TXBMT != 1)                  // wait until the command is moved into
   {                                   // the XMIT buffer
   }
   SPI0DAT = temp_addr.UByte[1];       // load the high byte of the address
   while (TXBMT != 1)                  // wait until the data is moved into
   {                                   // the XMIT buffer
   }
   SPI0DAT = temp_addr.UByte[2];       // load the middle byte of the address
   while (TXBMT != 1)                  // wait until the data is moved into
   {                                   // the XMIT buffer
   }
   SPI0DAT = temp_addr.UByte[3];       // load the low byte of the address
   while (TXBMT != 1)                  // wait until the data is moved into
   {                                   // the XMIT buffer
   }
   SPI0DAT = 0xFF;                     // load junk data in order to receive
                                       // data from the flash
   while (TXBMT != 1)                  // wait until the junk data is moved
   {                                   // into the XMIT buffer
   }
   SPIF = 0;
   while (SPIF != 1)                   // wait until the read data is received
   {
   }
   SPIF = 0;

   NSSMD0 = 1;                         // disable the flash

   return SPI0DAT;
}

//-----------------------------------------------------------------------------
// ReadID_MEM
//-----------------------------------------------------------------------------
//
// Return Value :
//   1)  char data_byte - the device ID read from memory at address 0x000001
//                      (this address is specified in the SST Flash datasheet)
//                      range is positive range of character: 0 to 255
// Parameters   : None
//
// Read the part ID from the flash memory (used for debugging).
//
/*
char ReadID_MEM (void)
{
   NSSMD0 = 0;                         // enable the flash

   SPI0DAT = READID;                   // send the read ID instruction
   while (TXBMT != 1)                  // wait until the SPI can accept more
   {                                   // data
   }
   SPI0DAT = 0x00;                     // send the device ID address
   while (TXBMT != 1)                  // wait until the SPI can accept more
   {                                   // data
   }
   SPI0DAT = 0x00;                     // send the device ID address
   while (TXBMT != 1)                  // wait until the SPI can accept more
   {                                   // data
   }
   SPI0DAT = 0x01;                     // send the device ID address
   while (TXBMT != 1)                  // wait until the SPI can accept more
   {                                   // data
   }
   SPI0DAT = 0xA5;                     // send dummy data for shift register
   while (TXBMT != 1)                  // wait until the SPI can accept more
   {                                   // data
   }
   SPIF = 0;
   while (SPIF != 1)                   // wait until the read data is received
   {
   }
   SPIF = 0;

   NSSMD0 = 1;                         // disable the flash

   return SPI0DAT;
}
*/
//-----------------------------------------------------------------------------
// End Of File
//-----------------------------------------------------------------------------