riscv/jtag_dtm.h

   1 #ifndef JTAG_DTM_H
   2 #define JTAG_DTM_H
   3
   4 #include <stdint.h>
   5
   6 typedef enum {
   7   TEST_LOGIC_RESET,
   8   RUN_TEST_IDLE,
   9   SELECT_DR_SCAN,
  10   CAPTURE_DR,
  11   SHIFT_DR,
  12   EXIT1_DR,
  13   PAUSE_DR,
  14   EXIT2_DR,
  15   UPDATE_DR,
  16   SELECT_IR_SCAN,
  17   CAPTURE_IR,
  18   SHIFT_IR,
  19   EXIT1_IR,
  20   PAUSE_IR,
  21   EXIT2_IR,
  22   UPDATE_IR
  23 } jtag_state_t;
  24
  25 class jtag_dtm_t
  26 {
  27   static const unsigned idcode_ir = 1;
  28   static const unsigned idcode_dr = 0xdeadbeef;
  29   static const unsigned dtmcontrol_ir = 0x10;
  30
  31   public:
  32     jtag_dtm_t() :
  33       dtmcontrol(
  34           (6 << 4) |        // abits
  35           1                 // version
  36           ),
  37       state(TEST_LOGIC_RESET) {}
  38
  39     void reset() {
  40       state = TEST_LOGIC_RESET;
  41     }
  42
  43     void set_pins(bool tck, bool tms, bool tdi);
  44
  45     bool tdo() const { return _tdo; }
  46
  47   private:
  48     bool _tck, _tms, _tdi, _tdo;
  49     uint32_t ir;
  50     const unsigned ir_length = 5;
  51     uint64_t dr;
  52     unsigned dr_length;
  53
  54     uint32_t dtmcontrol;
  55
  56     jtag_state_t state;
  57
  58     void capture_dr();
  59     void update_dr();
  60
  61     const jtag_state_t next[16][2] = {
  62       /* TEST_LOGIC_RESET */    { RUN_TEST_IDLE, TEST_LOGIC_RESET },
  63       /* RUN_TEST_IDLE */       { RUN_TEST_IDLE, SELECT_DR_SCAN },
  64       /* SELECT_DR_SCAN */      { CAPTURE_DR, SELECT_IR_SCAN },
  65       /* CAPTURE_DR */          { SHIFT_DR, EXIT1_DR },
  66       /* SHIFT_DR */            { SHIFT_DR, EXIT1_DR },
  67       /* EXIT1_DR */            { PAUSE_DR, UPDATE_DR },
  68       /* PAUSE_DR */            { PAUSE_DR, EXIT2_DR },
  69       /* EXIT2_DR */            { SHIFT_DR, UPDATE_DR },
  70       /* UPDATE_DR */           { RUN_TEST_IDLE, SELECT_DR_SCAN },
  71       /* SELECT_IR_SCAN */      { CAPTURE_IR, TEST_LOGIC_RESET },
  72       /* CAPTURE_IR */          { SHIFT_IR, EXIT1_IR },
  73       /* SHIFT_IR */            { SHIFT_IR, EXIT1_IR },
  74       /* EXIT1_IR */            { PAUSE_IR, UPDATE_IR },
  75       /* PAUSE_IR */            { PAUSE_IR, EXIT2_IR },
  76       /* EXIT2_IR */            { SHIFT_IR, UPDATE_IR },
  77       /* UPDATE_IR */           { RUN_TEST_IDLE, SELECT_DR_SCAN }
  78     };
  79 };
  80
  81 #endif