git.rot13.org Git - goodfet/blob - firmware/apps/pic/dspic33f.c

   1 /*! \file dspic33f.c
   2
   3   \author Scott Livingston
   4
   5   \brief dsPIC33F programmer application for the GoodFET. Structure
   6          and style is somewhat modeled after avr.c
   7
   8   \date March, April 2010
   9 */
  10
  11
  12 #include "apps.h"
  13 #include "platform.h"
  14 #include "command.h"
  15
  16 #include "dspic33f.h"
  17
  18
  19 void pic33f_setup()
  20 {
  21         // Initialize pins; do NOT begin transaction.
  22         P5DIR |= PGC|MCLR;
  23         P5REN &= ~(PGC|PGD|MCLR);
  24         DIR_PGD_WR; // Initially PGD in write mode
  25
  26         SET_MCLR;
  27         CLR_PGC;
  28         CLR_PGD;
  29
  30         prep_timer(); // What better time than now?
  31 }
  32
  33
  34 //! Handle a PIC command; currently assumes dsPIC33F/PIC24H
  35 void pichandle( unsigned char app,
  36                                 unsigned char verb,
  37                                 unsigned long len )
  38 {
  39         unsigned int nb; // Number of bytes
  40         unsigned int highb, loww; // Used for ICSP commands
  41
  42         switch (verb) {
  43
  44         case PIC_DEVID33F:
  45                 nb = pic33f_getid();
  46                 txdata(app,verb,nb);
  47                 break;
  48
  49         case PIC_SIX33F:
  50                 loww = *cmddata;
  51                 loww |= (*(cmddata+1)) << 8;
  52                 highb = *(cmddata+2);
  53                 pic33f_six( highb, loww );
  54                 txdata(app,verb,0);
  55                 break;
  56
  57         case PIC_SIXLIST33F:
  58                 pic33f_sixlist( len ); // Reply to host is handled by pic33f_sixlist.
  59                 break;
  60
  61         case PIC_REGOUT33F:
  62                 loww = pic33f_regout();
  63                 *cmddata = loww & 0xff;
  64                 *(cmddata+1) = loww >> 8;
  65                 txdata(app,verb,2);
  66                 break;
  67
  68         case PIC_START33F:
  69                 pic33f_connect();
  70                 txdata(app,verb,0);
  71                 break;
  72
  73         case PIC_STOP33F:
  74                 pic33f_disconnect();
  75                 txdata(app,verb,0);
  76                 break;
  77
  78         default:
  79                 debugstr( "Verb unimplemented in PIC application." );
  80                 txdata(app,NOK,0);
  81                 break;
  82
  83         }
  84 }
  85
  86
  87 void pic33f_trans8( unsigned char byte )
  88 {
  89         /* We only twiddle the PGD and PGC lines.
  90            MCLR is assumed to be in the correct state. */
  91         unsigned int i;
  92
  93         DIR_PGD_WR; // Write mode
  94         i = 1;
  95         while (i & 0xff) {
  96                 if (byte & i) {
  97                         SET_PGD;
  98                 } else {
  99                         CLR_PGD;
 100                 }
 101                 delay_ticks(10);
 102                 SET_PGC;
 103                 delay_ticks(10);
 104
 105                 CLR_PGC;
 106                 delay_ticks(10);
 107                 i = i << 1;
 108         }
 109         CLR_PGD;
 110         DIR_PGD_RD; // Read mode
 111 }
 112
 113 void pic33f_trans16( unsigned int word )
 114 {
 115         pic33f_trans8( word & 0xff );
 116         pic33f_trans8( word >> 8 );
 117 }
 118
 119
 120 void pic33f_six( unsigned int highb, unsigned int loww )
 121 {
 122         /* dsPIC33F/PIC24H instructions have width 24 bits, so we use the
 123            lower 8 bits of highb and (all 16 bits of) loww to form the
 124            instruction.
 125
 126            Shift in the instruction.  Note that it does not execute until
 127            the next 4 clock cycles (which also corresponds to a command
 128            receipt time). */
 129         unsigned int i;
 130         DIR_PGD_WR;
 131         CLR_PGD;
 132         CLR_PGC;
 133         for (i = 0; i < 4; i++) {
 134                 SET_PGC;
 135                 delay_ticks(10);
 136                 CLR_PGC;
 137                 delay_ticks(10);
 138         }
 139         pic33f_trans16( loww );
 140         pic33f_trans8( highb );
 141         DIR_PGD_RD;
 142 }
 143
 144
 145 unsigned int pic33f_regout()
 146 {
 147         unsigned int i;
 148         unsigned int result = 0x0000;
 149
 150         DIR_PGD_WR;
 151
 152         // Shift in command (REGOUT: 0001b).
 153         SET_PGD;
 154         delay_ticks(10);
 155         SET_PGC;
 156         delay_ticks(10);
 157         CLR_PGC;
 158         delay_ticks(10);
 159
 160         CLR_PGD;
 161         delay_ticks(10);
 162         for (i = 0; i < 3; i++) {
 163                 SET_PGC;
 164                 delay_ticks(10);
 165                 CLR_PGC;
 166                 delay_ticks(10);
 167         }
 168
 169         // Pump clock for 8 cycles, and switch PGD direction to read.
 170         for (i = 0; i < 7; i++) {
 171                 SET_PGC;
 172                 delay_ticks(10);
 173                 CLR_PGC;
 174                 delay_ticks(10);
 175         }
 176         DIR_PGD_RD;
 177
 178         /* Now read VISI register (LSb first, as usual).
 179        Note that when reading from attached device, data is valid (to
 180            be read) on falling clock edges. */
 181         for (i = 0; i < 16; i++) {
 182                 SET_PGC;
 183                 delay_ticks(10);
 184                 CLR_PGC;
 185                 result |= READ_PGD << i;
 186                 delay_ticks(10);
 187         }
 188
 189         /* One last tick apparently is needed here, at least by the
 190            dsPIC33FJ128GP708 chip that I am working with. Note that this
 191            is not in the flash programming specs. */
 192         SET_PGC;
 193         delay_ticks(10);
 194         CLR_PGC;
 195         delay_ticks(10);
 196
 197         return result;
 198 }
 199
 200
 201 void pic33f_sixlist( unsigned int list_len )
 202 {
 203         unsigned int k;
 204         unsigned int instr_loww;
 205
 206         // Bound to Rx buffer size.
 207         if (list_len > CMDDATALEN)
 208                 list_len = CMDDATALEN;
 209
 210         // Run each instruction!
 211         for (k = 0; k < list_len-2; k+=3) {
 212                 instr_loww = *(cmddata+k);
 213                 instr_loww |= (*(cmddata+k+1)) << 8;
 214                 pic33f_six( *(cmddata+k+2), instr_loww );
 215         }
 216
 217         // Reply with total number of bytes used from Rx buffer.
 218         txdata( PIC, PIC_SIXLIST33F, k );
 219 }
 220
 221
 222 unsigned int pic33f_getid()
 223 {
 224         unsigned int result;
 225         unsigned int nb = 0;
 226
 227         pic33f_connect();
 228
 229         // Read application ID.
 230         pic33f_six( 0x04, 0x0200 ); // goto 0x200 (i.e. reset)
 231         pic33f_six( 0x00, 0x0000 ); // nop
 232         pic33f_six( 0x20, 0x0800 ); // mov #0x80, W0
 233         pic33f_six( 0x88, 0x0190 ); // mov W0, TBLPAG
 234         pic33f_six( 0x20, 0x7F00 ); // mov #0x7F0, W0
 235         pic33f_six( 0x20, 0x7841 ); // mov #VISI, W1
 236         pic33f_six( 0x00, 0x0000 ); // nop
 237         pic33f_six( 0xBA, 0x0890 ); // TBLRDL [W0], [W1]
 238         pic33f_six( 0x00, 0x0000 ); // nop
 239         pic33f_six( 0x00, 0x0000 ); // nop
 240         result = pic33f_regout();
 241         *cmddata = result & 0xff;
 242         nb += 1;
 243
 244         // Read DEVID.
 245         pic33f_six( 0x20, 0x0FF0 ); // mov #0xFF, W0
 246         pic33f_six( 0x88, 0x0190 ); // mov W0, TBLPAG
 247         pic33f_six( 0xEB, 0x0000 ); // clr W0
 248         pic33f_six( 0x00, 0x0000 ); // nop
 249         pic33f_six( 0xBA, 0x08B0 ); // TBLRDL [W0++], [W1]
 250         pic33f_six( 0x00, 0x0000 ); // nop
 251         pic33f_six( 0x00, 0x0000 ); // nop
 252         result = pic33f_regout();
 253         *(cmddata+1) = result & 0xff;
 254         *(cmddata+2) = result >> 8;
 255         nb += 2;
 256
 257         // Read hardware revision.
 258         pic33f_six( 0xBA, 0x0890 ); // TBLRDL [W0++], [W1]
 259         pic33f_six( 0x00, 0x0000 ); // nop
 260         pic33f_six( 0x00, 0x0000 ); // nop
 261         result = pic33f_regout();
 262         *(cmddata+3) = result & 0xff;
 263         *(cmddata+4) = result >> 8;
 264         nb += 2;
 265
 266         pic33f_disconnect();
 267
 268         return nb;
 269 }
 270
 271
 272 void pic33f_connect()
 273 {
 274         unsigned int key_low;
 275         unsigned int key_high;
 276
 277         key_low = ICSP_KEY_LOW;
 278         key_high = ICSP_KEY_HIGH;
 279
 280         pic33f_setup();
 281
 282         CLR_PGC;
 283         delay_us(1);
 284
 285         CLR_MCLR;
 286         delay_ms(3);
 287         SET_MCLR;
 288         delay_us(200);
 289         CLR_MCLR;
 290         delay_us(10);
 291
 292         // Enter ICSP key
 293         pic33f_trans8( key_low & 0xff );
 294         key_low = key_low >> 8;
 295         pic33f_trans8( key_low & 0xff );
 296         pic33f_trans8( key_high & 0xff );
 297         key_high = key_high >> 8;
 298         pic33f_trans8( key_high & 0xff );
 299
 300         delay_us(1);
 301         SET_MCLR; // ...and pull MCLR pin back up.
 302         delay_ms(25); // Now wait about 25 ms (required per spec!).
 303
 304         /* The first ICSP command must be a SIX, and further, 9 bits are
 305        required before the instruction (to be executed), rather than
 306        the typical 4 bits. Thus, to simplify code, I simply load a nop
 307        here; hence 33 bits are shifted into the dsPIC33F/PIC24H. */
 308         DIR_PGD_WR;
 309         CLR_PGD;
 310         CLR_PGC;
 311         for (key_low = 0; key_low < 33; key_low++) {
 312                 SET_PGC;
 313                 delay_us(1);
 314                 CLR_PGC;
 315                 delay_us(1);
 316         }
 317         DIR_PGD_RD;
 318
 319 }
 320
 321
 322 void pic33f_disconnect()
 323 {
 324         DIR_PGD_WR;
 325         CLR_PGD;
 326         CLR_PGC;
 327         delay_ms(10);
 328         CLR_MCLR;
 329 }