src/actual_pinmux.py

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