X-Git-Url: http://git.rot13.org/?p=goodfet;a=blobdiff_plain;f=firmware%2Fapps%2Fjtag%2Fjtag.c;h=bda0fac41a8756a4fe2eb614ba67a9be2aea8b4b;hp=97db51bb408d78218da050a03835ea7e1a513b2c;hb=022d9128fe8a5783e3b804581fe7996d17095ef6;hpb=32145d206afbd4ee4c08c2c1543297e568667525 diff --git a/firmware/apps/jtag/jtag.c b/firmware/apps/jtag/jtag.c index 97db51b..bda0fac 100644 --- a/firmware/apps/jtag/jtag.c +++ b/firmware/apps/jtag/jtag.c @@ -8,19 +8,172 @@ #include "command.h" #include "jtag.h" +#define JTAG_APP + +//! Handles a monitor command. +void jtag_handle_fn(uint8_t const app, + uint8_t const verb, + uint32_t const len); + +//! JTAG device ID. +unsigned char jtagid=0; + +// define the jtag app's app_t +app_t const jtag_app = { + + /* app number */ + JTAG, + + /* handle fn */ + jtag_handle_fn, + + /* name */ + "JTAG", + + /* desc */ + "\tThe JTAG app handles basic JTAG operations such as\n" + "\tresetting the TAP, resetting the target, detecting\n" + "\tthe instruction register width, shifting bits into\n" + "\tboth the instruction and data registers.\n" +}; + //! 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; @@ -52,7 +205,7 @@ unsigned char jtagtrans8(unsigned char byte){ } //! Shift n bits in and out. -unsigned long jtagtransn(unsigned long word, +/*unsigned long jtagtransn(unsigned long word, unsigned int bitcount){ unsigned int bit; //0x8000 @@ -66,7 +219,7 @@ unsigned long jtagtransn(unsigned long word, SAVETCLK; for (bit = 0; bit < bitcount; bit++) { - /* write MOSI on trailing edge of previous clock */ + // write MOSI on trailing edge of previous clock * if (word & high) {SETMOSI;} else @@ -77,7 +230,7 @@ unsigned long jtagtransn(unsigned long word, SETTMS;//TMS high on last bit to exit. TCKTOCK; - /* read MISO on trailing edge */ + // read MISO on trailing edge * word |= READMISO; } @@ -95,7 +248,7 @@ unsigned long jtagtransn(unsigned long word, return word; } - +*/ //! Stop JTAG, release pins void jtag_stop(){ @@ -103,7 +256,7 @@ void jtag_stop(){ P4OUT=0; } -unsigned int drwidth=20; +unsigned int drwidth=16; //! Shift all bits of the DR. unsigned long jtag_dr_shift20(unsigned long in){ // idle @@ -116,7 +269,7 @@ unsigned long jtag_dr_shift20(unsigned long in){ TCKTOCK; // shift DR, then idle - return(jtagtransn(in,20)); + return(jtagtransn(in,20,0)); } @@ -132,7 +285,27 @@ unsigned int jtag_dr_shift16(unsigned int in){ TCKTOCK; // shift DR, then idle - return(jtagtransn(in,16)); + 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; + TCKTOCK; + // capture IR + TCKTOCK; + + + out=jtagtransn(in,drwidth,0); + + // shift DR, then idle + return(out); } @@ -154,30 +327,41 @@ unsigned char jtag_ir_shift8(unsigned char in){ } //! Handles a monitor command. -void jtaghandle(unsigned char app, - unsigned char verb, - unsigned long len){ - switch(verb){ - //START handled by specific JTAG - case STOP: - jtag_stop(); - txdata(app,verb,0); - break; - case SETUP: - jtagsetup(); - txdata(app,verb,0); - break; - case JTAG_IR_SHIFT: - cmddata[0]=jtag_ir_shift8(cmddata[0]); - txdata(app,verb,1); - break; - case JTAG_DR_SHIFT: - cmddataword[0]=jtag_dr_shift16(cmddataword[0]); - txdata(app,verb,2); - break; - default: - txdata(app,NOK,0); - } +void jtag_handle_fn(uint8_t const app, + uint8_t const verb, + uint32_t const len) +{ + switch(verb) + { + //START handled by specific JTAG + case STOP: + jtag_stop(); + txdata(app,verb,0); + break; + + case SETUP: + jtagsetup(); + txdata(app,verb,0); + break; + + case JTAG_IR_SHIFT: + cmddata[0]=jtag_ir_shift8(cmddata[0]); + txdata(app,verb,1); + break; + + case JTAG_DR_SHIFT: + 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); + } }