X-Git-Url: http://git.rot13.org/?p=goodfet;a=blobdiff_plain;f=firmware%2Fapps%2Fjtag%2Fjtag.c;h=050e2055c17555b4641f9de18e2753163b5831f6;hp=af420c7095afd854aa7866dc8a082fdd24a5a4e2;hb=5fb0341d348e101b30794945a6c91546e25e8e7b;hpb=dd37f96a4f842ea15233b8d0efd4ec001ad5de9c

diff --git a/firmware/apps/jtag/jtag.c b/firmware/apps/jtag/jtag.c
index af420c7..050e205 100644
--- a/firmware/apps/jtag/jtag.c
+++ b/firmware/apps/jtag/jtag.c
@@ -1,23 +1,176 @@
-//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"
 
+#define JTAG_APP
+
+//! Handles a monitor command.
+void jtag_handle_fn(uint8_t const app,
+					uint8_t const verb,
+					uint32_t const len);
+
+// 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(){
   P5DIR|=MOSI+SCK+TMS;
   P5DIR&=~MISO;
+  /*
   P5OUT|=0xFFFF;
+  P5OUT=0;
+  */
   P4DIR|=TST;
   P2DIR|=RST;
+  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;
@@ -33,30 +186,27 @@ unsigned char jtagtrans8(unsigned char byte){
     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 n bits in and out.
-unsigned long jtagtransn(unsigned long word,
+/*unsigned long jtagtransn(unsigned long word,
 			 unsigned int bitcount){
   unsigned int bit;
   //0x8000
-  unsigned long high;
+  unsigned long high=0x8000;
   
   if(bitcount==20)
     high=0x80000;
@@ -66,7 +216,7 @@ unsigned long jtagtransn(unsigned long word,
   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
@@ -76,9 +226,8 @@ unsigned long jtagtransn(unsigned long word,
     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;
   }
   
@@ -89,50 +238,14 @@ unsigned long jtagtransn(unsigned long word,
   RESTORETCLK;
   
   // exit state
-  CLRTCK;
-  SETTCK;
+  TCKTOCK;
   // update state
   CLRTMS;
-  CLRTCK;
-  SETTCK;
+  TCKTOCK;
   
   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;
-  }
-  RESTORETCLK;
-  
-  // exit state
-  CLRTCK;
-  SETTCK;
-  // update state
-  CLRTMS;
-  CLRTCK;
-  SETTCK;
-  
-  return word;
-}*/
+*/
 
 //! Stop JTAG, release pins
 void jtag_stop(){
@@ -140,23 +253,20 @@ void jtag_stop(){
   P4OUT=0;
 }
 
-unsigned int drwidth=20;
+unsigned int drwidth=16;
 //! Shift all bits of the DR.
 unsigned long jtag_dr_shift20(unsigned long in){
   // idle
   SETTMS;
-  CLRTCK;
-  SETTCK;
+  TCKTOCK;
   // select DR
   CLRTMS;
-  CLRTCK;
-  SETTCK;
+  TCKTOCK;
   // capture IR
-  CLRTCK;
-  SETTCK;
+  TCKTOCK;
   
   // shift DR, then idle
-  return(jtagtransn(in,20));
+  return(jtagtransn(in,20,0));
 }
 
 
@@ -164,18 +274,35 @@ unsigned long jtag_dr_shift20(unsigned long in){
 unsigned int jtag_dr_shift16(unsigned int in){
   // idle
   SETTMS;
-  CLRTCK;
-  SETTCK;
+  TCKTOCK;
+  // select DR
+  CLRTMS;
+  TCKTOCK;
+  // capture IR
+  TCKTOCK;
+  
+  // shift DR, then idle
+  return(jtagtransn(in,16,0));
+}
+
+//! Shift native width of the DR
+unsigned long jtag_dr_shiftadr(unsigned long in){
+  unsigned long out=0;
+  
+  // idle
+  SETTMS;
+  TCKTOCK;
   // select DR
   CLRTMS;
-  CLRTCK;
-  SETTCK;
+  TCKTOCK;
   // capture IR
-  CLRTCK;
-  SETTCK;
+  TCKTOCK;
+
+  
+  out=jtagtransn(in,drwidth,0);
   
   // shift DR, then idle
-  return(jtagtransn(in,16));
+  return(out);
 }
 
 
@@ -183,48 +310,55 @@ unsigned int jtag_dr_shift16(unsigned int in){
 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){
-  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);
+	}
 }