git.rot13.org Git - goodfet/blob - client/GoodFETJTAG.py

   1 #!/usr/bin/env python
   2 # GoodFET Basic JTAG Client
   3
   4 import sys, binascii, struct
   5
   6 # Standard verbs
   7 READ  = 0x00
   8 WRITE = 0x01
   9 PEEK  = 0x02
  10 POKE  = 0x03
  11 SETUP = 0x10
  12 START = 0x20
  13 STOP  = 0x21
  14 CALL  = 0x30
  15 EXEC  = 0x31
  16 NOK   = 0x7E
  17 OK    = 0x7F
  18
  19 # JTAG commands
  20 JTAG_RESET_TAP              = 0x82
  21 JTAG_RESET_TARGET           = 0x83
  22 JTAG_DETECT_IR_WIDTH        = 0x84
  23 JTAG_DETECT_CHAIN_LENGTH    = 0x85
  24 JTAG_GET_DEVICE_ID          = 0x86
  25
  26 from GoodFET import GoodFET
  27 from intelhex import IntelHex
  28
  29 class GoodFETJTAG(GoodFET):
  30
  31     """A GoodFET variant for basic JTAG'ing."""
  32
  33     JTAGAPP=0x10;
  34     APP=JTAGAPP;
  35
  36     def _check_return(self, verb, length=0):
  37         if (self.app == self.APP) and \
  38            (self.verb == verb) and \
  39            (len(self.data) == length):
  40             print "OK"
  41             return True
  42         print "Failed!"
  43         return False
  44
  45     def setup(self):
  46         """Move the FET into the JTAG configuration."""
  47         sys.stdout.write("Initializing JTAG...")
  48         self.writecmd(self.APP, SETUP)
  49         self._check_return(SETUP)
  50
  51     def reset_tap(self):
  52         sys.stdout.write("Resetting TAP...")
  53         self.writecmd(self.APP, JTAG_RESET_TAP)
  54         self._check_return(JTAG_RESET_TAP)
  55
  56     def reset_target(self):
  57         sys.stdout.write("Resseting target device...")
  58         self.writecmd(self.APP, JTAG_RESET_TARGET)
  59         self._check_return(JTAG_RESET_TARGET)
  60
  61     def detect_ir_width(self):
  62         sys.stdout.write("Detecting IR width...")
  63         self.writecmd(self.APP, JTAG_DETECT_IR_WIDTH)
  64         self._check_return(JTAG_DETECT_IR_WIDTH, 2)
  65         width = struct.unpack("!H", self.data)[0]
  66         return width
  67
  68     def detect_chain_length(self):
  69         sys.stdout.write("Detecting chain length...")
  70         self.writecmd(self.APP, JTAG_DETECT_CHAIN_LENGTH)
  71         self._check_return(JTAG_DETECT_CHAIN_LENGTH, 2)
  72         length = struct.unpack("!H", self.data)[0]
  73         return length
  74
  75     def get_device_id(self, chip):
  76         sys.stdout.write("Getting ID for device %d..." % chip)
  77         self.writecmd(self.APP, JTAG_GET_DEVICE_ID, 2, struct.pack("!H", chip))
  78         self._check_return(JTAG_GET_DEVICE_ID, 4)
  79         id = struct.unpack("!L", self.data)[0]
  80         return id
  81
  82