src/actual_pinmux.py

   1 from params 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 pinmap_file = open("./pinmap.txt", "r")
  35 dedicated = False
  36 for lineno, line in enumerate(pinmap_file):
  37     line1 = line.split()
  38     if("muxed" in line):
  39         dedicated = False
  40     elif("dedicated" in line):
  41         dedicated = True
  42     digits = str.maketrans(dict.fromkeys('0123456789'))
  43     # ==== Logic for muxed pins ==== #
  44     if(len(line1) > 1 and not(dedicated)):
  45         if(lineno > N_IO):
  46             print(
  47                 "ERROR: Parameter N_IO(" +
  48                 str(N_IO) +
  49                 ") is less than the pin number in line: " +
  50                 str(lineno) +
  51                 " of pinmap.txt")
  52             exit(1)
  53         # ==== Mux each generic IO cell with the mapping ===== #
  54         # provided in the pinmap file
  55         pinmux = pinmux + "      cell" + str(line1[0]) + "_out="
  56         i = 0
  57         while(i < len(line1) - 1):
  58             pinmux = pinmux + "wrmux" + \
  59                 str(line1[0]) + "==" + str(i) + "?" + line1[i + 1] + "_io:"
  60             if(i + 2 == len(line1) - 1):
  61                 pinmux = pinmux + line1[i + 2] + "_io"
  62                 i = i + 2
  63             else:
  64                 i = i + 1
  65         pinmux = pinmux + ";\n"
  66         # ======================================================== #
  67
  68         # check each cell if "peripheral input/inout" then assign its wire
  69         # Here we check the direction of each signal in the dictionary.
  70         # We choose to keep the dictionary within the code and not user-input
  71         # since the interfaces are always standard and cannot change from
  72         # user-to-user. Plus this also reduces human-error as well :)
  73         for i in range(0, len(line1) - 1):
  74             temp = line1[i + 1].translate(digits)
  75             x = dictionary.get(temp)
  76             if(x is None):
  77                 print(
  78                     "Error: The signal : " +
  79                     str(line1[i + 1]) +
  80                     " in lineno: " +
  81                     str(lineno) + "of pinmap.txt isn't present in the \
  82                     current dictionary.\nUpdate dictionary or fix-typo.")
  83                 exit(1)
  84             if(x == "input"):
  85                 pinmux = pinmux + \
  86                     mux_wire.format(line1[0], i, "wr" + line1[i + 1]) + "\n"
  87             elif(x == "inout"):
  88                 pinmux = pinmux + \
  89                     mux_wire.format(line1[0], i, "wr" + line1[i + 1] +
  90                                     "_in") + "\n"
  91         # ============================================================ #
  92
  93     # ==================  Logic for dedicated pins ========= #
  94     elif(len(line1) > 1 and dedicated):
  95         pinmux = pinmux + "      cell" + \
  96             str(line1[0]) + "_out=" + line1[1] + "_io;\n"
  97         temp = line1[1].translate(digits)
  98         x = dictionary.get(temp)
  99         if(x == "input"):
 100             pinmux = pinmux + \
 101                 dedicated_wire.format(line1[0], "wr" + line1[1]) + "\n"
 102         elif(x == "inout"):
 103             pinmux = pinmux + \
 104                 dedicated_wire.format(line1[0], "wr" + line1[1] + "_in") + "\n"
 105     # ======================================================= #
 106 # =========================================================