src/bsv/actual_pinmux.py

   1 from string import digits
   2 try:
   3     from string import maketrans
   4 except ImportError:
   5     maketrans = str.maketrans
   6
   7
   8 # dictionary of properties of signals that are supported.
   9 dictionary = {
  10     "uart_rx"   : "input",
  11     "uart_tx"   : "output",
  12     "spi_sclk"  : "output",
  13     "spi_mosi"  : "output",
  14     "spi_ss"    : "output",
  15     "spi_miso"  : "input",
  16     "twi_sda"   : "inout",
  17     "twi_scl"   : "inout",
  18     "sd_clk": "output",
  19     "sd_cmd": "output",
  20     "sd_d": "inout",
  21     "pwm_pwm": "output"
  22 }
  23
  24
  25 # ============== common bsv templates ============ #
  26 # first argument is the io-cell number being assigned.
  27 # second argument is the mux value.
  28 # Third argument is the signal from the pinmap file
  29 mux_wire = '''
  30       rule assign_{2}_on_cell{0}(wrcell{0}_mux=={1});
  31         {2}<=cell{0}_mux_in;
  32       endrule
  33 '''
  34 dedicated_wire = '''
  35       rule assign_{1}_on_cell{0};
  36         {1}<=cell{0}_mux_in;
  37       endrule
  38 '''
  39 # ============================================================
  40 digits = maketrans('0123456789', ' ' * 10)  # delete space later
  41
  42
  43 def cn(idx):
  44     return "cell%s_mux" % str(idx)
  45
  46
  47 def init(p):
  48     p.pinmux = ' '
  49     global dedicated_wire
  50     for cell in p.muxed_cells:
  51         p.pinmux += "      %s_out=" % cn(cell[0])
  52         for i in range(0, len(cell) - 2):
  53             p.pinmux += "wr%s" % cn(cell[0]) + \
  54                 "==" + str(i) + "?" + cell[i + 1] + "_io:\n\t\t\t"
  55         p.pinmux += cell[i + 2] + "_io"
  56         p.pinmux += ";\n"
  57         # ======================================================== #
  58
  59         # check each cell if "peripheral input/inout" then assign its wire
  60         # Here we check the direction of each signal in the dictionary.
  61         # We choose to keep the dictionary within the code and not user-input
  62         # since the interfaces are always standard and cannot change from
  63         # user-to-user. Plus this also reduces human-error as well :)
  64         for i in range(0, len(cell) - 1):
  65             temp = cell[i + 1].translate(digits)
  66             temp = temp.replace(' ', '')
  67             x = dictionary.get(temp)
  68             assert x is not None, "ERROR: The signal : " + \
  69                 str(cell[i + 1]) + \
  70                 " of pinmap.txt isn't present \nin the current" + \
  71                 " dictionary. Update dictionary or fix-typo."
  72             if x == "input":
  73                 p.pinmux += \
  74                     mux_wire.format(cell[0], i, "wr" + cell[i + 1]) + "\n"
  75             elif x == "inout":
  76                 p.pinmux += \
  77                     mux_wire.format(cell[0], i, "wr" + cell[i + 1] +
  78                                                 "_in") + "\n"
  79     # ============================================================ #
  80
  81     # ==================  Logic for dedicated pins ========= #
  82     for cell in p.dedicated_cells:
  83         p.pinmux += "      %s" % cn(cell[0]) + \
  84             "_out=" + cell[1] + "_io;\n"
  85         temp = cell[1].translate(digits)
  86         x = dictionary.get(temp)
  87         if x == "input":
  88             pinmux = pinmux + \
  89                 dedicated_wire.format(cell[0], "wr" + cell[1]) + "\n"
  90         elif x == "inout":
  91             pinmux = pinmux + \
  92                 dedicated_wire.format(cell[0], "wr" + cell[1] + "_in") + "\n"
  93     # =======================================================#