#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(){
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;
}
//! 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
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
SETTMS;//TMS high on last bit to exit.
TCKTOCK;
- /* read MISO on trailing edge */
+ // read MISO on trailing edge *
word |= READMISO;
}
return word;
}
-
+*/
//! Stop JTAG, release pins
void jtag_stop(){
TCKTOCK;
// shift DR, then idle
- return(jtagtransn(in,20));
+ return(jtagtransn(in,20,0));
}
TCKTOCK;
// shift DR, then idle
- return(jtagtransn(in,16));
+ return(jtagtransn(in,16,0));
}
//! Shift native width of the DR
TCKTOCK;
- out=jtagtransn(in,drwidth);
+ out=jtagtransn(in,drwidth,0);
// shift DR, then idle
return(out);
}
//! 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);
+ }
}
projects / goodfet / blobdiff