Some bits of Spy-Bi-Wire support, thanks to Mark Rages. (Not yet complete.)

[goodfet] / firmware / apps / jtag / jtag.c

diff --git a/firmware/apps/jtag/jtag.c b/firmware/apps/jtag/jtag.c
index 4dc7021..20c4360 100644 (file)
--- a/firmware/apps/jtag/jtag.c
+++ b/firmware/apps/jtag/jtag.c
@@ -1,7 +1,8 @@
-//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"
@@ -13,8 +14,10 @@ void jtagsetup(){
   P5DIR|=MOSI+SCK+TMS;
   P5DIR&=~MISO;
   P5OUT|=0xFFFF;
+  P5OUT=0;
   P4DIR|=TST;
   P2DIR|=RST;
+  msdelay(100);
 }
 
 int savedtclk=0;
@@ -55,11 +58,19 @@ unsigned char jtagtrans8(unsigned char byte){
 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 < bitcount; bit++) {
     /* write MOSI on trailing edge of previous clock */
-    if (word & 0x8000)
+    if (word & high)
       {SETMOSI;}
     else
       {CLRMOSI;}
@@ -73,41 +84,11 @@ unsigned long jtagtransn(unsigned long word,
     /* read MISO on trailing edge */
     word |= READMISO;
   }
-  RESTORETCLK;
-  
-  // exit state
-  CLRTCK;
-  SETTCK;
-  // update state
-  CLRTMS;
-  CLRTCK;
-  SETTCK;
   
-  return word;
-}
-
-/*
-//! Shift 16 bits in and out.
-unsigned int jtagtrans16(unsigned int word){ //REMOVEME
-  unsigned int bit;
-  SAVETCLK;
-  
-  for (bit = 0; bit < 16; bit++) {
-    // write MOSI on trailing edge of previous clock 
-    if (word & 0x8000)
-      {SETMOSI;}
-    else
-      {CLRMOSI;}
-    word <<= 1;
-    
-    if(bit==15)
-      SETTMS;//TMS high on last bit to exit.
-    
-    CLRTCK;
-    SETTCK;
-    // read MISO on trailing edge 
-    word |= READMISO;
+  if(bitcount==20){
+    word = ((word << 16) | (word >> 4)) & 0x000FFFFF;
   }
+  
   RESTORETCLK;
   
   // exit state
@@ -119,7 +100,8 @@ unsigned int jtagtrans16(unsigned int word){ //REMOVEME
   SETTCK;
   
   return word;
-}*/
+}
+
 
 //! Stop JTAG, release pins
 void jtag_stop(){
@@ -129,7 +111,7 @@ void jtag_stop(){
 
 unsigned int drwidth=20;
 //! Shift all bits of the DR.
-unsigned long jtag_dr_shift(unsigned long in){
+unsigned long jtag_dr_shift20(unsigned long in){
   // idle
   SETTMS;
   CLRTCK;
@@ -143,14 +125,26 @@ unsigned long jtag_dr_shift(unsigned long in){
   SETTCK;
   
   // shift DR, then idle
-  return(jtagtransn(in,drwidth));
+  return(jtagtransn(in,20));
 }
 
 
 //! Shift 16 bits of the DR.
 unsigned int jtag_dr_shift16(unsigned int in){
-  //This name is deprecated, kept around to find 16-bit dependent code.
-  return jtag_dr_shift(in);
+  // idle
+  SETTMS;
+  CLRTCK;
+  SETTCK;
+  // select DR
+  CLRTMS;
+  CLRTCK;
+  SETTCK;
+  // capture IR
+  CLRTCK;
+  SETTCK;
+  
+  // shift DR, then idle
+  return(jtagtransn(in,16));
 }
 
 
@@ -178,7 +172,7 @@ 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: