X-Git-Url: http://git.rot13.org/?p=goodfet;a=blobdiff_plain;f=firmware%2Fapps%2Fjtag%2Fjtag.c;h=cc6ef169e874bac278989732913352d1f5359a73;hp=2b04a81ea9e793b878a21606c6d6435ca53f97b6;hb=ec842a71bc86390267ca8dffdd5cf8236dc211e4;hpb=3bf98a899ca8003835b69d949d299369a5d7a4f7 diff --git a/firmware/apps/jtag/jtag.c b/firmware/apps/jtag/jtag.c index 2b04a81..cc6ef16 100644 --- a/firmware/apps/jtag/jtag.c +++ b/firmware/apps/jtag/jtag.c @@ -1,25 +1,144 @@ -//GoodFET JTAG Application -//Handles basic I/O +/*! \file jtag.c + \author Travis Goodspeed + \brief Low-level JTAG +*/ -//Higher level left to client application. #include "platform.h" #include "command.h" #include "jtag.h" - - //! Set up the pins for JTAG mode. void jtagsetup(){ P5DIR|=MOSI+SCK+TMS; P5DIR&=~MISO; + /* P5OUT|=0xFFFF; + P5OUT=0; + */ P4DIR|=TST; P2DIR|=RST; + msdelay(100); +} + +/************************** JTAG Primitives ****************************/ +// these have been turned into functions to save flash space +void jtag_tcktock() { + CLRTCK; + PLEDOUT^=PLEDPIN; + SETTCK; + PLEDOUT^=PLEDPIN; +} + +void jtag_goto_shift_ir() { + SETTMS; + jtag_tcktock(); + jtag_tcktock(); + CLRTMS; + jtag_tcktock(); + jtag_tcktock(); + +} +void jtag_goto_shift_dr() { + SETTMS; + jtag_tcktock(); + CLRTMS; + jtag_tcktock(); + jtag_tcktock(); +} + +void jtag_resettap(){ + SETTMS; + jtag_tcktock(); + jtag_tcktock(); + jtag_tcktock(); + jtag_tcktock(); + jtag_tcktock(); // now in Reset state + CLRTMS; + jtag_tcktock(); // now in Run-Test/Idle state } + int savedtclk=0; +// NOTE: important: THIS MODULE REVOLVES AROUND RETURNING TO RUNTEST/IDLE, OR THE FUNCTIONAL EQUIVALENT +//! Shift N bits over TDI/TDO. May choose LSB or MSB, and select whether to terminate (TMS-high on last bit) and whether to return to RUNTEST/IDLE +// flags should be 0 for most uses. +// for the extreme case, flags should be (NOEND|NORETDLE|LSB) +// other edge cases can involve a combination of those three flags +// +// the max bit-size that can be be shifted is 32-bits. +// for longer shifts, use the NOEND flag (which infers NORETIDLE so the additional flag is unnecessary) +// +// NORETIDLE is used for special cases where (as with arm) the debug subsystem does not want to +// return to the RUN-TEST/IDLE state between setting IR and DR +unsigned long jtagtransn(unsigned long word, unsigned char bitcount, unsigned char flags){ + unsigned char bit; + unsigned long high = 1L; + unsigned long mask; + + //for (bit=(bitcount-1)/8; bit>0; bit--) + // high <<= 8; + //high <<= ((bitcount-1)%8); + high <<= (bitcount-1); + + mask = high-1; + + SAVETCLK; + if (flags & LSB) { + for (bit = bitcount; bit > 0; bit--) { + /* write MOSI on trailing edge of previous clock */ + if (word & 1) + {SETMOSI;} + else + {CLRMOSI;} + word >>= 1; + + if (bit==1 && !(flags & NOEND)) + SETTMS;//TMS high on last bit to exit. + + jtag_tcktock(); + + /* read MISO on trailing edge */ + if (READMISO){ + word += (high); + } + } + } else { + for (bit = bitcount; bit > 0; bit--) { + /* write MOSI on trailing edge of previous clock */ + if (word & high) + {SETMOSI;} + else + {CLRMOSI;} + word = (word & mask) << 1; + + if (bit==1 && !(flags & NOEND)) + SETTMS;//TMS high on last bit to exit. + + jtag_tcktock(); + + /* read MISO on trailing edge */ + word |= (READMISO); + } + } + + + RESTORETCLK; + //SETMOSI; + + if (!(flags & NOEND)){ + // exit state + jtag_tcktock(); + // update state + if (!(flags & NORETIDLE)){ + CLRTMS; + jtag_tcktock(); + } + } + return word; +} + //! Shift 8 bits in and out. unsigned char jtagtrans8(unsigned char byte){ unsigned int bit; @@ -35,57 +154,66 @@ unsigned char jtagtrans8(unsigned char byte){ if(bit==7) SETTMS;//TMS high on last bit to exit. - CLRTCK; - SETTCK; - /* read MISO on trailing edge */ + TCKTOCK; + /* read MISO on trailing edge */ byte |= READMISO; } RESTORETCLK; // exit state - CLRTCK; - SETTCK; + TCKTOCK; // update state CLRTMS; - CLRTCK; - SETTCK; + TCKTOCK; return byte; } -//! Shift 8 bits in and out. -unsigned int jtagtrans16(unsigned int word){ +//! Shift n bits in and out. +/*unsigned long jtagtransn(unsigned long word, + unsigned int bitcount){ unsigned int bit; + //0x8000 + unsigned long high=0x8000; + + if(bitcount==20) + high=0x80000; + if(bitcount==16) + high= 0x8000; + SAVETCLK; - for (bit = 0; bit < 16; bit++) { - /* write MOSI on trailing edge of previous clock */ - if (word & 0x8000) + for (bit = 0; bit < bitcount; bit++) { + // write MOSI on trailing edge of previous clock * + if (word & high) {SETMOSI;} else {CLRMOSI;} word <<= 1; - if(bit==15) + if(bit==bitcount-1) SETTMS;//TMS high on last bit to exit. - CLRTCK; - SETTCK; - /* read MISO on trailing edge */ + TCKTOCK; + // read MISO on trailing edge * word |= READMISO; } + + if(bitcount==20){ + word = ((word << 16) | (word >> 4)) & 0x000FFFFF; + } + RESTORETCLK; // exit state - CLRTCK; - SETTCK; + TCKTOCK; // update state CLRTMS; - CLRTCK; - SETTCK; + TCKTOCK; return word; } +*/ //! Stop JTAG, release pins void jtag_stop(){ @@ -93,23 +221,56 @@ void jtag_stop(){ P4OUT=0; } +unsigned int drwidth=16; +//! Shift all bits of the DR. +unsigned long jtag_dr_shift20(unsigned long in){ + // idle + SETTMS; + TCKTOCK; + // select DR + CLRTMS; + TCKTOCK; + // capture IR + TCKTOCK; + + // shift DR, then idle + return(jtagtransn(in,20,0)); +} + //! Shift 16 bits of the DR. unsigned int jtag_dr_shift16(unsigned int in){ // idle SETTMS; - CLRTCK; - SETTCK; + TCKTOCK; + // select DR + CLRTMS; + TCKTOCK; + // capture IR + TCKTOCK; + + // shift DR, then idle + return(jtagtransn(in,16,0)); +} + +//! Shift native width of the DR +unsigned long jtag_dr_shiftadr(unsigned long in){ + unsigned long out=0; + + // idle + SETTMS; + TCKTOCK; // select DR CLRTMS; - CLRTCK; - SETTCK; + TCKTOCK; // capture IR - CLRTCK; - SETTCK; + TCKTOCK; + + out=jtagtransn(in,drwidth,0); + // shift DR, then idle - return(jtagtrans16(in)); + return(out); } @@ -117,18 +278,14 @@ unsigned int jtag_dr_shift16(unsigned int in){ unsigned char jtag_ir_shift8(unsigned char in){ // idle SETTMS; - CLRTCK; - SETTCK; + TCKTOCK; // select DR - CLRTCK; - SETTCK; + TCKTOCK; // select IR CLRTMS; - CLRTCK; - SETTCK; + TCKTOCK; // capture IR - CLRTCK; - SETTCK; + TCKTOCK; // shift IR, then idle. return(jtagtrans8(in)); @@ -137,7 +294,7 @@ unsigned char jtag_ir_shift8(unsigned char in){ //! Handles a monitor command. void jtaghandle(unsigned char app, unsigned char verb, - unsigned char len){ + unsigned long len){ switch(verb){ //START handled by specific JTAG case STOP: @@ -156,6 +313,10 @@ void jtaghandle(unsigned char app, cmddataword[0]=jtag_dr_shift16(cmddataword[0]); txdata(app,verb,2); break; + case JTAG_RESETTAP: + jtag_resettap(); + txdata(app,verb,0); + break; default: txdata(app,NOK,0); }