-//GoodFET JTAG Application
-//Handles basic I/O
+/*! \file jtag.c
+ \author Travis Goodspeed <travis at radiantmachines.com>
+ \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.
-unsigned char jtagsetup(){
+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;
for (bit = 0; bit < 8; bit++) {
/* write MOSI on trailing edge of previous clock */
if (byte & 0x80)
- SETMOSI;
+ {SETMOSI;}
else
- CLRMOSI;
+ {CLRMOSI;}
byte <<= 1;
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)
- SETMOSI;
+ for (bit = 0; bit < bitcount; bit++) {
+ // write MOSI on trailing edge of previous clock *
+ if (word & high)
+ {SETMOSI;}
else
- CLRMOSI;
+ {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(){
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);
}
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));
//! 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:
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);
}
projects / goodfet / blobdiff