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 2b04a81..20c4360 100644 (file)
--- a/firmware/apps/jtag/jtag.c
+++ b/firmware/apps/jtag/jtag.c
@@ -1,22 +1,23 @@
-//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.
 void jtagsetup(){
   P5DIR|=MOSI+SCK+TMS;
   P5DIR&=~MISO;
   P5OUT|=0xFFFF;
+  P5OUT=0;
   P4DIR|=TST;
   P2DIR|=RST;
+  msdelay(100);
 }
 
 int savedtclk=0;
@@ -53,27 +54,41 @@ unsigned char jtagtrans8(unsigned char byte){
   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 */
+    /* read MISO on trailing edge */
     word |= READMISO;
   }
+  
+  if(bitcount==20){
+    word = ((word << 16) | (word >> 4)) & 0x000FFFFF;
+  }
+  
   RESTORETCLK;
   
   // exit state
@@ -87,12 +102,32 @@ unsigned int jtagtrans16(unsigned int word){
   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;
+  CLRTCK;
+  SETTCK;
+  // select DR
+  CLRTMS;
+  CLRTCK;
+  SETTCK;
+  // capture IR
+  CLRTCK;
+  SETTCK;
+  
+  // shift DR, then idle
+  return(jtagtransn(in,20));
+}
+
 
 //! Shift 16 bits of the DR.
 unsigned int jtag_dr_shift16(unsigned int in){
@@ -107,9 +142,9 @@ unsigned int jtag_dr_shift16(unsigned int in){
   // capture IR
   CLRTCK;
   SETTCK;
-
+  
   // shift DR, then idle
-  return(jtagtrans16(in));
+  return(jtagtransn(in,16));
 }
 
 
@@ -137,7 +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: