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     "pwm": "output"
  19 }
  20
  21
  22 # ============== common bsv templates ============ #
  23 # first argument is the io-cell number being assigned.
  24 # second argument is the mux value.
  25 # Third argument is the signal from the pinmap file
  26 mux_wire = '''
  27       rule assign_{2}_on_cell{0}(wrmux{0}=={1});
  28         {2}<=cell{0}_in;
  29       endrule
  30 '''
  31 dedicated_wire = '''
  32       rule assign_{1}_on_cell{0};
  33         {1}<=cell{0}_in;
  34       endrule
  35 '''
  36 # ============================================================
  37 pinmux = ''' '''
  38 digits = str.maketrans(dict.fromkeys('0123456789'))
  39
  40 for cell in muxed_cells:
  41     pinmux = pinmux + "      cell" + str(cell[0]) + "_out="
  42     i = 0
  43     while(i < len(cell) - 1):
  44         pinmux = pinmux + "wrmux" + \
  45             str(cell[0]) + "==" + str(i) + "?" + cell[i + 1] + "_io:"
  46         if(i + 2 == len(cell) - 1):
  47             pinmux = pinmux + cell[i + 2] + "_io"
  48             i = i + 2
  49         else:
  50             i = i + 1
  51     pinmux = pinmux + ";\n"
  52     # ======================================================== #
  53
  54     # check each cell if "peripheral input/inout" then assign its wire
  55     # Here we check the direction of each signal in the dictionary.
  56     # We choose to keep the dictionary within the code and not user-input
  57     # since the interfaces are always standard and cannot change from
  58     # user-to-user. Plus this also reduces human-error as well :)
  59     for i in range(0, len(cell) - 1):
  60         temp = cell[i + 1].translate(digits)
  61         x = dictionary.get(temp)
  62         if(x is None):
  63             print(
  64               "ERROR: The signal : " +
  65               str(cell[i + 1]) +
  66               " of pinmap.txt isn't present in the current dictionary.\
  67               \nUpdate dictionary or fix-typo.")
  68             exit(1)
  69         if(x == "input"):
  70             pinmux = pinmux + \
  71               mux_wire.format(cell[0], i, "wr" + cell[i + 1]) + "\n"
  72         elif(x == "inout"):
  73             pinmux = pinmux + \
  74                 mux_wire.format(cell[0], i, "wr" + cell[i + 1] +
  75                                             "_in") + "\n"
  76 # ============================================================ #
  77
  78 # ==================  Logic for dedicated pins ========= #
  79 for cell in dedicated_cells:
  80     pinmux = pinmux + "      cell" + \
  81         str(cell[0]) + "_out=" + cell[1] + "_io;\n"
  82     temp = cell[1].translate(digits)
  83     x = dictionary.get(temp)
  84     if(x == "input"):
  85         pinmux = pinmux + \
  86             dedicated_wire.format(cell[0], "wr" + cell[1]) + "\n"
  87     elif(x == "inout"):
  88         pinmux = pinmux + \
  89             dedicated_wire.format(cell[0], "wr" + cell[1] + "_in") + "\n"
  90 # =======================================================#