Writing of SPI Flash works just after it is plugged in,

[goodfet] / firmware / apps / spi / spi.c

diff --git a/firmware/apps/spi/spi.c b/firmware/apps/spi/spi.c
index b0b5323..c58b4bc 100644 (file)
--- a/firmware/apps/spi/spi.c
+++ b/firmware/apps/spi/spi.c
@@ -28,8 +28,11 @@
 #define CLRCLK P5OUT&=~SCK
 #define READMISO (P5IN&MISO?1:0)
 
+
+
 //! Set up the pins for SPI mode.
-unsigned char spisetup(){
+void spisetup(){
+  P5OUT|=SS;
   P5DIR|=MOSI+SCK+SS;
   P5DIR&=~MISO;
 }
@@ -39,7 +42,7 @@ unsigned char spitrans8(unsigned char byte){
   unsigned int bit;
   //This function came from the SPI Wikipedia article.
   //Minor alterations.
- 
+  
   for (bit = 0; bit < 8; bit++) {
     /* write MOSI on trailing edge of previous clock */
     if (byte & 0x80)
@@ -59,20 +62,95 @@ unsigned char spitrans8(unsigned char byte){
     byte |= READMISO;
     CLRCLK;
   }
- 
+  
   return byte;
 }
 
+//! Enable SPI writing
+void spiflash_wrten(){
+  P5OUT&=~SS; //Drop !SS to begin transaction.
+  spitrans8(0x04);//Write Disable
+  P5OUT|=SS;  //Raise !SS to end transaction.
+  P5OUT&=~SS; //Drop !SS to begin transaction.
+  spitrans8(0x06);//Write Enable
+  P5OUT|=SS;  //Raise !SS to end transaction.
+}
+
+//! Grab the SPI flash status byte.
+unsigned char spiflash_status(){
+  unsigned char c;
+  P5OUT&=~SS; //Drop !SS to begin transaction.
+  spitrans8(0x05);//GET STATUS
+  c=spitrans8(0xFF);
+  P5OUT|=SS;  //Raise !SS to end transaction.
+  return c;
+}
+//! Grab the SPI flash status byte.
+void spiflash_setstatus(unsigned char c){
+  P5OUT&=~SS; //Drop !SS to begin transaction.
+  spitrans8(0x01);//SET STATUS
+  spitrans8(c);
+  P5OUT|=SS;  //Raise !SS to end transaction.
+  return c;
+}
+
 //! Handles a monitor command.
 void spihandle(unsigned char app,
               unsigned char verb,
               unsigned char len){
+  unsigned char i;
   switch(verb){
     //PEEK and POKE might come later.
   case READ:
   case WRITE:
-    cmddata[0]=spitrans8(cmddata[0]);
-    txdata(app,verb,1);
+    P5OUT&=~SS; //Drop !SS to begin transaction.
+    for(i=0;i<len;i++)
+      cmddata[i]=spitrans8(cmddata[i]);
+    P5OUT|=SS;  //Raise !SS to end transaction.
+    txdata(app,verb,len);
+    break;
+  case SPI_JEDEC://Grab 3-byte JEDEC ID.
+    P5OUT&=~SS; //Drop !SS to begin transaction.
+    spitrans8(0x9f);
+    len=3;
+    for(i=0;i<len;i++)
+      cmddata[i]=spitrans8(cmddata[i]);
+    txdata(app,verb,len);
+    P5OUT|=SS;  //Raise !SS to end transaction.
+    break;
+  case PEEK://Grab 128 bytes from an SPI Flash ROM
+    P5OUT&=~SS; //Drop !SS to begin transaction.
+    spitrans8(0x03);//Flash Read Command
+    len=3;//write 3 byte pointer
+    for(i=0;i<len;i++)
+      spitrans8(cmddata[i]);
+    len=0x80;//128 byte chunk
+    for(i=0;i<len;i++)
+      cmddata[i]=spitrans8(0);
+    txdata(app,verb,len);
+    P5OUT|=SS;  //Raise !SS to end transaction.
+    break;
+  case POKE://Poke up bytes from an SPI Flash ROM.
+    spiflash_setstatus(0x02);
+    spiflash_wrten();
+    
+    P5OUT&=~SS; //Drop !SS to begin transaction.
+    spitrans8(0x02); //Poke command.
+    
+    //First three bytes are address, then data.
+    for(i=0;i<len;i++)
+      spitrans8(cmddata[i]);
+    P5OUT&=~SS; //Drop !SS to begin transaction.
+    while(spiflash_status()&0x01);//while busy
+    spiflash_wrten();
+    txdata(app,verb,len);
+    break;
+  case SPI_ERASE://Erase the SPI Flash ROM.
+    spiflash_wrten();
+    P5OUT&=~SS; //Drop !SS to begin transaction.
+    spitrans8(0xC7);//Chip Erase
+    P5OUT|=SS;  //Raise !SS to end transaction.
+    txdata(app,verb,0);
     break;
   case SETUP:
     spisetup();