X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;ds=sidebyside;f=firmware%2Fapps%2Fjtag%2Fjtag.c;h=cf9199d90fbca16c6ced460f7cb9fd2aa352fa59;hb=ce0bba3cfbf4844bdce1f6984af24d1f78c347f1;hp=5abba15cb43d6cee14365179c5b8f38f1a01c690;hpb=3e4369fde16445c994da1b1efb332704aad0716d;p=goodfet

diff --git a/firmware/apps/jtag/jtag.c b/firmware/apps/jtag/jtag.c
index 5abba15..cf9199d 100644
--- a/firmware/apps/jtag/jtag.c
+++ b/firmware/apps/jtag/jtag.c
@@ -1,7 +1,12 @@
-//GoodFET JTAG Application
-//Handles basic I/O
+/*! \file jtag.c
+  \author Travis Goodspeed <travis at radiantmachines.com>
+  
+  This is an implementation of the low-level JTAG functions
+  for the GoodFET project at http://goodfet.sf.net/
+  
+  See the license file for details of proper use.
+*/
 
-//Higher level left to client application.
 
 #include "platform.h"
 #include "command.h"
@@ -13,8 +18,10 @@ void jtagsetup(){
   P5DIR|=MOSI+SCK+TMS;
   P5DIR&=~MISO;
   P5OUT|=0xFFFF;
+  P5OUT=0;
   P4DIR|=TST;
   P2DIR|=RST;
+  msdelay(100);
 }
 
 int savedtclk=0;
@@ -55,14 +62,19 @@ unsigned char jtagtrans8(unsigned char byte){
 unsigned long jtagtransn(unsigned long word,
 			 unsigned int bitcount){
   unsigned int bit;
-  unsigned int high=(word>>16);
-  SAVETCLK;
+  //0x8000
+  unsigned long high;
   
+  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;}
@@ -137,7 +149,7 @@ 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;
@@ -151,14 +163,26 @@ 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));
 }