-//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"
P5DIR|=MOSI+SCK+TMS;
P5DIR&=~MISO;
P5OUT|=0xFFFF;
+ P5OUT=0;
P4DIR|=TST;
P2DIR|=RST;
+ msdelay(100);
}
int savedtclk=0;
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++) {
+ for (bit = 0; bit < bitcount; bit++) {
/* write MOSI on trailing edge of previous clock */
- if (word & 0x8000)
+ 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(){
P5OUT=0;
P4OUT=0;
}
+unsigned int drwidth=20;
+//! 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));
+}
+
//! Shift 16 bits of the DR.
unsigned int jtag_dr_shift16(unsigned int in){
// idle
SETTMS;
- CLRTCK;
- SETTCK;
+ TCKTOCK;
// select DR
CLRTMS;
- CLRTCK;
- SETTCK;
+ TCKTOCK;
// capture IR
- CLRTCK;
- SETTCK;
-
+ TCKTOCK;
+
// shift DR, then idle
- return(jtagtrans16(in));
+ return(jtagtransn(in,16));
}
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: