X-Git-Url: http://git.rot13.org/?p=goodfet;a=blobdiff_plain;f=firmware%2Fapps%2Fspi%2Fspi.c;h=f02d4022146479c4622f2edf15c5f23a3bfe36f5;hp=5e762050839135e5c4fc270bee9a95108e3f59a2;hb=78f4f21969789bec27a8e2957eb00a87d8756041;hpb=fd966b09563a102ed42b1613e7fa5e934eed2656 diff --git a/firmware/apps/spi/spi.c b/firmware/apps/spi/spi.c index 5e76205..f02d402 100644 --- a/firmware/apps/spi/spi.c +++ b/firmware/apps/spi/spi.c @@ -1,5 +1,7 @@ -//GoodFET SPI Application -//Handles basic I/O +/*! \file spi.c + \author Travis Goodspeed + \brief SPI Master +*/ //Higher level left to client application. @@ -10,36 +12,30 @@ #include #include - -//Pins and I/O -#define SS BIT0 -#define MOSI BIT1 -#define MISO BIT2 -#define SCK BIT3 +#include //This could be more accurate. //Does it ever need to be? #define SPISPEED 0 -#define SPIDELAY(x) delay(x) - -#define SETMOSI P5OUT|=MOSI -#define CLRMOSI P5OUT&=~MOSI -#define SETCLK P5OUT|=SCK -#define CLRCLK P5OUT&=~SCK -#define READMISO (P5IN&MISO?1:0) - +#define SPIDELAY(x) +//delay(x) //! Set up the pins for SPI mode. -unsigned char spisetup(){ +void spisetup(){ + P5OUT|=SS; P5DIR|=MOSI+SCK+SS; P5DIR&=~MISO; + + //Begin a new transaction. + P5OUT&=~SS; P5OUT|=SS; } -//! Read and write an SPI bit. + +//! Read and write an SPI byte. unsigned char spitrans8(unsigned char byte){ - unsigned int bit; + register unsigned int bit; //This function came from the SPI Wikipedia article. //Minor alterations. @@ -51,13 +47,8 @@ unsigned char spitrans8(unsigned char byte){ CLRMOSI; byte <<= 1; - /* half a clock cycle before leading/rising edge */ - SPIDELAY(SPISPEED/2); SETCLK; - - /* half a clock cycle before trailing/falling edge */ - SPIDELAY(SPISPEED/2); - + /* read MISO on trailing edge */ byte |= READMISO; CLRCLK; @@ -66,24 +57,203 @@ unsigned char spitrans8(unsigned char byte){ return byte; } + +//! Enable SPI writing +void spiflash_wrten(){ + SETSS; + /* + 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; //Raise !SS to end transaction. + 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){ + SETSS; + CLRSS; //Drop !SS to begin transaction. + spitrans8(0x01);//SET STATUS + spitrans8(c); + SETSS; //Raise !SS to end transaction. + //return c; +} + + +//! Read a block to a buffer. +void spiflash_peekblock(unsigned long adr, + unsigned char *buf, + unsigned int len){ + unsigned char i; + + SETSS; + CLRSS; //Drop !SS to begin transaction. + spitrans8(0x03);//Flash Read Command + + //Send address + spitrans8((adr&0xFF0000)>>16); + spitrans8((adr&0xFF00)>>8); + spitrans8(adr&0xFF); + + for(i=0;i0x100?0x100:len-off); + //write the block + spiflash_pokeblock(adr+off, + buf+off, + blen); + //add offset + off+=blen; + } +} + +//! Read a block to a buffer. +void spiflash_pokeblock(unsigned long adr, + unsigned char *buf, + unsigned int len){ + unsigned int i; + + SETSS; + + //while(spiflash_status()&0x01);//minor performance impact + + //Are these necessary? + //spiflash_setstatus(0x02); + //spiflash_wrten(); + + CLRSS; //Drop !SS to begin transaction. + spitrans8(0x02); //Poke command. + + //Send address + spitrans8((adr&0xFF0000)>>16); + spitrans8((adr&0xFF00)>>8); + spitrans8(adr&0xFF); + + for(i=0;i