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     "sd_clk": "output",
  16     "sd_cmd": "output",
  17     "sd_d": "inout",
  18 }
  19
  20
  21 # ============== common bsv templates ============ #
  22 # first argument is the io-cell number being assigned.
  23 # second argument is the mux value.
  24 # Third argument is the signal from the pinmap file
  25 mux_wire = '''
  26       rule assign_{2}_on_cell{0}(wrmux{0}=={1});
  27         {2}<=cell{0}_in;
  28       endrule
  29 '''
  30 dedicated_wire = '''
  31       rule assign_{1}_on_cell{0};
  32         {1}<=cell{0}_in;
  33       endrule
  34 '''
  35 # ============================================================
  36 pinmux = ''' '''
  37 digits = str.maketrans(dict.fromkeys('0123456789'))
  38
  39 for cell in muxed_cells:
  40     pinmux = pinmux + "      cell" + str(cell[0]) + "_out="
  41     i = 0
  42     while(i < len(cell) - 1):
  43         pinmux = pinmux + "wrmux" + \
  44             str(cell[0]) + "==" + str(i) + "?" + cell[i + 1] + "_io:"
  45         if(i + 2 == len(cell) - 1):
  46             pinmux = pinmux + cell[i + 2] + "_io"
  47             i = i + 2
  48         else:
  49             i = i + 1
  50     pinmux = pinmux + ";\n"
  51     # ======================================================== #
  52
  53     # check each cell if "peripheral input/inout" then assign its wire
  54     # Here we check the direction of each signal in the dictionary.
  55     # We choose to keep the dictionary within the code and not user-input
  56     # since the interfaces are always standard and cannot change from
  57     # user-to-user. Plus this also reduces human-error as well :)
  58     for i in range(0, len(cell) - 1):
  59         temp = cell[i + 1].translate(digits)
  60         x = dictionary.get(temp)
  61         if(x is None):
  62             print(
  63               "ERROR: The signal : " +
  64               str(cell[i + 1]) +
  65               " of pinmap.txt isn't present in the current dictionary.\
  66               \nUpdate dictionary or fix-typo.")
  67             exit(1)
  68         if(x == "input"):
  69             pinmux = pinmux + \
  70               mux_wire.format(cell[0], i, "wr" + cell[i + 1]) + "\n"
  71         elif(x == "inout"):
  72             pinmux = pinmux + \
  73                 mux_wire.format(cell[0], i, "wr" + cell[i + 1] +
  74                                             "_in") + "\n"
  75 # ============================================================ #
  76
  77 # ==================  Logic for dedicated pins ========= #
  78 for cell in dedicated_cells:
  79     pinmux = pinmux + "      cell" + \
  80         str(cell[0]) + "_out=" + cell[1] + "_io;\n"
  81     temp = cell[1].translate(digits)
  82     x = dictionary.get(temp)
  83     if(x == "input"):
  84         pinmux = pinmux + \
  85             dedicated_wire.format(cell[0], "wr" + cell[1]) + "\n"
  86     elif(x == "inout"):
  87         pinmux = pinmux + \
  88             dedicated_wire.format(cell[0], "wr" + cell[1] + "_in") + "\n"
  89 # =======================================================#