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, idx):
  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     idx += 1
  55     if idx < len(cell):
  56         cell = cell[idx]
  57     else:
  58         cell = ''
  59     return "%s_io" % cell if cell else '0'
  60
  61
  62 def mkcomment(p, cell, idx):
  63     """ returns a comment string for the cell when muxed
  64     """
  65     return ""
  66
  67 def init(p, ifaces):
  68     """ generates the actual output pinmux for each io-cell.  blank lines
  69         need to output "0" to the iopad, if there is no entry in
  70         that column.
  71
  72         text is outputted in the format:
  73             x_out =
  74                 muxer_sel==0 ? a :
  75                 muxer_sel==1 ? b :
  76                 muxer_sel==2 ? 0 :
  77                 d
  78
  79         last line doesn't need selector-logic, obviously.
  80
  81         note that it's *important* that all muxer options be covered
  82         (hence going up to 1<<cell_bitwidth) even if the muxer cells
  83         are blank (no entries), because muxer selection could be to
  84         the last one, and we do not want the "default" (last line)
  85         to be the output.
  86     """
  87     p.cell_bitwidth = get_cell_bit_width(p)
  88     p.pinmux = ' '
  89     global dedicated_wire
  90     fmtstr = "\t\t\twr%s == %d ? %s :%s\n" # mux-selector format
  91     for cell in p.muxed_cells:
  92         p.pinmux += "      // output muxer for cell idx %s\n" % cell[0]
  93         p.pinmux += "      %s_out=\n" % cn(cell[0])
  94         for i in range(0, (1<<p.cell_bitwidth)-1): # full mux range (minus 1)
  95             comment = mkcomment(p, cell, i)
  96             p.pinmux += fmtstr % (cn(cell[0]), i, fmt(cell, i), comment)
  97         comment = mkcomment(p, cell, i+1)
  98         p.pinmux += "\t\t\t" + fmt(cell, i+1) + comment # last line
  99         p.pinmux += ";\n"
 100         # ======================================================== #
 101
 102         # check each cell if "peripheral input/inout" then assign its wire
 103         # Here we check the direction of each signal in the dictionary.
 104         # We choose to keep the dictionary within the code and not user-input
 105         # since the interfaces are always standard and cannot change from
 106         # user-to-user. Plus this also reduces human-error as well :)
 107         for i in range(0, len(cell) - 1):
 108             cname = cell[i + 1]
 109             if not cname: # skip blank entries, no need to test
 110                 continue
 111             temp = transfn(cname)
 112             x = ifaces.getifacetype(temp)
 113             #print (cname, temp, x)
 114             assert x is not None, "ERROR: The signal : " + \
 115                 str(cname) + \
 116                 " of pinmap.txt isn't present \nin the current" + \
 117                 " dictionary. Update dictionary or fix-typo."
 118             if x == "input":
 119                 p.pinmux += \
 120                     mux_wire.format(cell[0], i, "wr" + cname) + "\n"
 121             elif x == "inout":
 122                 p.pinmux += \
 123                     mux_wire.format(cell[0], i, "wr" + cname +
 124                                                 "_in") + "\n"
 125     # ============================================================ #
 126
 127     # ==================  Logic for dedicated pins ========= #
 128     for cell in p.dedicated_cells:
 129         p.pinmux += "      %s_out=%s_io;\n" % (cn(cell[0]), cell[1])
 130         temp = cell[1].translate(digits)
 131         x = ifaces.getifacetype(temp)
 132         if x == "input":
 133             pinmux = pinmux + \
 134                 dedicated_wire.format(cell[0], "wr" + cell[1]) + "\n"
 135         elif x == "inout":
 136             pinmux = pinmux + \
 137                 dedicated_wire.format(cell[0], "wr" + cell[1] + "_in") + "\n"
 138     # =======================================================#