src/pru-down.S

   1 /*
   2  * Copyright (c) 2016, Ian Sutton <ian@kremlin.cc>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for
   5  * any purpose with or without fee is hereby granted, provided that the
   6  * above copyright notice and this permission notice appear in all
   7  * copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
  10  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
  11  * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
  12  * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  13  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  14  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  15  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  16  * PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 .origin 0
  20 .entrypoint START /* used by debugger only */
  21
  22 #define PRU0_R31_VEC_VALID (1<<5)
  23 #define SIGNUM 3 /* corresponds to PRU_EVTOUT_0 */
  24
  25 #define DELAY_SECONDS 5
  26 #define CLOCK 200000000
  27 #define CLOCKS_PER_LOOP 2
  28 #define DELAYCOUNT DELAY_SECONDS * CLOCK / CLOCKS_PER_LOOP
  29
  30
  31 #define R_PINKY 0x0
  32 #define R_RING  0x1
  33 #define R_MID   0x10
  34 #define R_FORE  0x11
  35 #define R_THUMB 0x100
  36 #define L_THUMB 0x101
  37 #define L_FORE  0x110
  38 #define L_MID   0x111
  39 #define L_RING  0x1000
  40 #define L_PINKY 0x1001
  41
  42 #define CYCLE 4000000
  43 #define WIDTH_UP 120000
  44 #define WIDTH_DOWN 480000
  45
  46 //      MOV     r1, DELAYCOUNT
  47 //      ADD     r1, r1, r1
  48 //      ADD     r1, r1, r1
  49 //      ADD     r1, r1, r1
  50 //      ADD     r1, r1, r1
  51 //DELAY:
  52         //SUB   r1, r1, 1
  53         //NOT   r30, r30, r30
  54         //QBNE  DELAY, r1, 0
  55
  56 START:
  57
  58         MOV     r1, CYCLE
  59         MOV     r2, WIDTH_UP
  60         MOV     r3, WIDTH_DOWN
  61         MOV     r4, 0xffffffff
  62         MOV     r30, 0x000003ff
  63         MOV     r5, 0x00000000
  64 KLOOP:
  65         QBLE    DOWN, r5, r3
  66         QBLE    KRST, r5, r1
  67         ADD     r5, r5, 4
  68         JMP     KLOOP
  69 DOWN:
  70         MOV     r30, 0x00000000
  71         MOV     r3, 0xffffffff
  72         JMP     KLOOP
  73 KRST:
  74         MOV r5, 0x00000000
  75         MOV r30, 0x000003ff
  76         MOV r3, WIDTH_DOWN
  77         JMP KLOOP
  78 KHALT:
  79         MOV     R31.b0, PRU0_R31_VEC_VALID | SIGNUM
  80         HALT
  81