git.rot13.org Git - goodfet/blob - firmware/apps/jtag/jtag430.c

   1
   2 #include "platform.h"
   3 #include "command.h"
   4 #include "jtag.h"
   5
   6
   7 //! Set the program counter.
   8 void jtag430_setpc(unsigned int adr){
   9   jtag_ir_shift8(IR_CNTRL_SIG_16BIT);
  10   jtag_dr_shift16(0x3401);// release low byte
  11   jtag_ir_shift8(IR_DATA_16BIT);
  12   jtag_dr_shift16(0x4030);//Instruction to load PC
  13   CLRTCLK;
  14   SETTCLK;
  15   jtag_dr_shift16(adr);// Value for PC
  16   CLRTCLK;
  17   jtag_ir_shift8(IR_ADDR_CAPTURE);
  18   SETTCLK;
  19   CLRTCLK ;// Now PC is set to "PC_Value"
  20   jtag_ir_shift8(IR_CNTRL_SIG_16BIT);
  21   jtag_dr_shift16(0x2401);// low byte controlled by JTAG
  22 }
  23
  24 //! Halt the CPU
  25 void jtag430_haltcpu(){
  26   //jtag430_setinstrfetch();
  27
  28   jtag_ir_shift8(IR_DATA_16BIT);
  29   jtag_dr_shift16(0x3FFF);//JMP $+0
  30
  31   CLRTCLK;
  32   jtag_ir_shift8(IR_CNTRL_SIG_16BIT);
  33   jtag_dr_shift16(0x2409);//set JTAG_HALT bit
  34   SETTCLK;
  35 }
  36
  37 //! Release the CPU
  38 void jtag430_releasecpu(){
  39   CLRTCLK;
  40   jtag_ir_shift8(IR_CNTRL_SIG_16BIT);
  41   jtag_dr_shift16(0x2401);
  42   jtag_ir_shift8(IR_ADDR_CAPTURE);
  43   SETTCLK;
  44 }
  45
  46 //! Read data from address
  47 unsigned int jtag430_readmem(unsigned int adr){
  48   unsigned int toret;
  49
  50   CLRTCLK;
  51   jtag_ir_shift8(IR_CNTRL_SIG_16BIT);
  52   if(adr>0xFF)
  53     jtag_dr_shift16(0x2409);//word read
  54   else
  55     jtag_dr_shift16(0x2419);//byte read
  56   jtag_ir_shift8(IR_ADDR_16BIT);
  57   jtag_dr_shift16(adr);//address
  58   jtag_ir_shift8(IR_DATA_TO_ADDR);
  59   SETTCLK;
  60
  61   CLRTCLK;
  62   toret=jtag_dr_shift16(0x0000);//16 bit return
  63
  64   return toret;
  65 }
  66
  67 //! Write data to address.
  68 void jtag430_writemem(unsigned int adr, unsigned int data){
  69   CLRTCLK;
  70   jtag_ir_shift8(IR_CNTRL_SIG_16BIT);
  71   if(adr>0xFF)
  72     jtag_dr_shift16(0x2408);//word write
  73   else
  74     jtag_dr_shift16(0x2418);//byte write
  75   jtag_ir_shift8(IR_ADDR_16BIT);
  76   jtag_dr_shift16(adr);
  77   jtag_ir_shift8(IR_DATA_TO_ADDR);
  78   jtag_dr_shift16(data);
  79   SETTCLK;
  80
  81 }
  82
  83 //! Write data to address.
  84 void jtag430_writeflash(unsigned int adr, unsigned int data){
  85   //TODO; this is complicated.
  86 }
  87
  88
  89 //! Reset the TAP state machine.
  90 void jtag430_resettap(){
  91   int i;
  92   // Settle output
  93   SETTMS;
  94   SETTDI;
  95   SETTCK;
  96
  97   // Navigate to reset state.
  98   // Should be at least six.
  99   for(i=0;i<4;i++){
 100     CLRTCK;
 101     SETTCK;
 102   }
 103
 104   // test-logic-reset
 105   CLRTCK;
 106   CLRTMS;
 107   SETTCK;
 108   SETTMS;
 109   // idle
 110
 111
 112   /* sacred, by spec.
 113      Sometimes this isn't necessary. */
 114   // fuse check
 115   CLRTMS;
 116   delay(50);
 117   SETTMS;
 118   CLRTMS;
 119   delay(50);
 120   SETTMS;
 121   /**/
 122
 123 }
 124
 125 //! Start JTAG, take pins
 126 void jtag430_start(){
 127   jtagsetup();
 128
 129   //Known-good starting position.
 130   //Might be unnecessary.
 131   SETTST;
 132   SETRST;
 133   delay(0xFFFF);
 134
 135   //Entry sequence from Page 67 of SLAU265A for 4-wire MSP430 JTAG
 136   CLRRST;
 137   delay(100);
 138   CLRTST;
 139   delay(50);
 140   SETTST;
 141   delay(50);
 142   SETRST;
 143   P5DIR&=~RST;
 144   delay(0xFFFF);
 145 }
 146
 147 //! Set CPU to Instruction Fetch
 148 void jtag430_setinstrfetch(){
 149   jtag_ir_shift8(IR_CNTRL_SIG_CAPTURE);
 150
 151   // Wait until instruction fetch state.
 152   while(1){
 153     if (jtag_dr_shift16(0x0000) & 0x0080)
 154       return;
 155     CLRTCLK;
 156     SETTCLK;
 157   }
 158 }
 159
 160 //! Handles unique MSP430 JTAG commands.  Forwards others to JTAG.
 161 void jtag430handle(unsigned char app,
 162                    unsigned char verb,
 163                    unsigned char len){
 164   unsigned char i;
 165   switch(verb){
 166   case START:
 167     //Enter JTAG mode.
 168     jtag430_start();
 169     //TAP setup, fuse check
 170     jtag430_resettap();
 171     txdata(app,verb,0);
 172     break;
 173   case JTAG430_HALTCPU:
 174     jtag430_haltcpu();
 175     txdata(app,verb,0);
 176     break;
 177   case JTAG430_RELEASECPU:
 178     jtag430_releasecpu();
 179     txdata(app,verb,0);
 180     break;
 181   case JTAG430_SETINSTRFETCH:
 182     jtag430_setinstrfetch();
 183     txdata(app,verb,0);
 184     break;
 185
 186
 187   case JTAG430_READMEM:
 188   case PEEK:
 189     cmddataword[0]=jtag430_readmem(cmddataword[0]);
 190     txdata(app,verb,2);
 191     break;
 192   case JTAG430_WRITEMEM:
 193   case POKE:
 194     jtag430_writemem(cmddataword[0],cmddataword[1]);
 195     txdata(app,verb,0);
 196     break;
 197   case JTAG430_WRITEFLASH:
 198     jtag430_writeflash(cmddataword[0],cmddataword[1]);
 199     txdata(app,verb,0);
 200     break;
 201   case JTAG430_SETPC:
 202     jtag430_setpc(cmddataword[0]);
 203     txdata(app,verb,0);
 204     break;
 205   default:
 206     jtaghandle(app,verb,len);
 207   }
 208 }
 209