src/bsv/actual_pinmux.py

   1 import math
   2 from string import digits
   3 try:
   4     from string import maketrans
   5 except ImportError:
   6     maketrans = str.maketrans
   7
   8
   9 # ============== common bsv templates ============ #
  10 # first argument is the io-cell number being assigned.
  11 # second argument is the mux value.
  12 # Third argument is the signal from the pinmap file
  13 mux_wire = '''
  14       rule assign_{2}_on_cell{0}(wrcell{0}_mux=={1});
  15         {2}<=cell{0}_mux_in;
  16       endrule
  17 '''
  18 dedicated_wire = '''
  19       rule assign_{1}_on_cell{0};
  20         {1}<=cell{0}_mux_in;
  21       endrule
  22 '''
  23 # ============================================================
  24 digits = maketrans('0123456789', ' ' * 10)  # delete space later
  25
  26
  27 def get_cell_bit_width(p):
  28     max_num_cells = 0
  29     for cell in p.muxed_cells:
  30         max_num_cells = max(len(cell) - 1, max_num_cells)
  31     return int(math.log(max_num_cells+1, 2))
  32
  33
  34 def cn(idx):  # idx is an integer
  35     return "cell%s_mux" % str(idx)
  36
  37
  38 def transfn(temp):
  39     """ removes the number from the string of signal name.
  40     """
  41     temp = temp.split('_')
  42     if len(temp) == 2:
  43         temp[0] = temp[0].translate(digits)
  44         temp[0] = temp[0] .replace(' ', '')
  45     return '_'.join(temp)
  46
  47 def fmt(cell):
  48     """ blank entries need to output a 0 to the pin (it could just as
  49         well be a 1 but we choose 0).  reason: blank entries in
  50         the pinmap.txt file indicate that there's nothing to choose
  51         from.  however the user may still set the muxer to that value,
  52         and rather than throw an exception we choose to output... zero.
  53     """
  54     return "%s_io" % cell if cell else '0'
  55
  56
  57 def mkcomment(p, cell):
  58     """ returns a comment string for the cell when muxed
  59     """
  60     return ""
  61
  62 def init(p, ifaces):
  63     """ generates the actual output pinmux for each io-cell.  blank lines
  64         need to output "0" to the iopad, if there is no entry in
  65         that column.
  66
  67         text is outputted in the format:
  68             x_out =
  69                 muxer_sel==0 ? a :
  70                 muxer_sel==1 ? b :
  71                 muxer_sel==2 ? 0 :
  72                 d
  73
  74         last line doesn't need selector-logic, obviously.
  75     """
  76     p.cell_bitwidth = get_cell_bit_width(p)
  77     p.pinmux = ' '
  78     global dedicated_wire
  79     fmtstr = "\t\t\twr%s == %d ? %s :%s\n" # mux-selector format
  80     for cell in p.muxed_cells:
  81         p.pinmux += "      // output muxer for cell idx %s\n" % cell[0]
  82         p.pinmux += "      %s_out=\n" % cn(cell[0])
  83         for i in range(0, len(cell) - 2):
  84             comment = mkcomment(p, cell[i + 1])
  85             p.pinmux += fmtstr % (cn(cell[0]), i, fmt(cell[i + 1]), comment)
  86         comment = mkcomment(p, cell[i + 2])
  87         p.pinmux += "\t\t\t" + fmt(cell[i + 2]) + comment # last line
  88         p.pinmux += ";\n"
  89         # ======================================================== #
  90
  91         # check each cell if "peripheral input/inout" then assign its wire
  92         # Here we check the direction of each signal in the dictionary.
  93         # We choose to keep the dictionary within the code and not user-input
  94         # since the interfaces are always standard and cannot change from
  95         # user-to-user. Plus this also reduces human-error as well :)
  96         for i in range(0, len(cell) - 1):
  97             cname = cell[i + 1]
  98             if not cname: # skip blank entries, no need to test
  99                 continue
 100             temp = transfn(cname)
 101             x = ifaces.getifacetype(temp)
 102             #print (cname, temp, x)
 103             assert x is not None, "ERROR: The signal : " + \
 104                 str(cname) + \
 105                 " of pinmap.txt isn't present \nin the current" + \
 106                 " dictionary. Update dictionary or fix-typo."
 107             if x == "input":
 108                 p.pinmux += \
 109                     mux_wire.format(cell[0], i, "wr" + cname) + "\n"
 110             elif x == "inout":
 111                 p.pinmux += \
 112                     mux_wire.format(cell[0], i, "wr" + cname +
 113                                                 "_in") + "\n"
 114     # ============================================================ #
 115
 116     # ==================  Logic for dedicated pins ========= #
 117     for cell in p.dedicated_cells:
 118         p.pinmux += "      %s_out=%s_io;\n" % (cn(cell[0]), cell[1])
 119         temp = cell[1].translate(digits)
 120         x = ifaces.getifacetype(temp)
 121         if x == "input":
 122             pinmux = pinmux + \
 123                 dedicated_wire.format(cell[0], "wr" + cell[1]) + "\n"
 124         elif x == "inout":
 125             pinmux = pinmux + \
 126                 dedicated_wire.format(cell[0], "wr" + cell[1] + "_in") + "\n"
 127     # =======================================================#