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 cn(idx):  # idx is an integer
  28     return "cell%s_mux" % str(idx)
  29
  30
  31 def transfn(temp):
  32     """ removes the number from the string of signal name.
  33     """
  34     temp = temp.split('_')
  35     if len(temp) == 2:
  36         temp[0] = temp[0].translate(digits)
  37         temp[0] = temp[0] .replace(' ', '')
  38     return '_'.join(temp)
  39
  40
  41 # XXX this needs to move into interface_decl.py
  42 # and made to use ifaceoutfmtfn and ifaceinfmtfn
  43 def fmt(ifaces, cells, idx, suffix=None):
  44     """ blank entries need to output a 0 to the pin (it could just as
  45         well be a 1 but we choose 0).  reason: blank entries in
  46         the pinmap.txt file indicate that there's nothing to choose
  47         from.  however the user may still set the muxer to that value,
  48         and rather than throw an exception we choose to output... zero.
  49
  50         NOTE: IMPORTANT.  when a function is an output-only there
  51         is a special-case assumption that:
  52         * (a) GPIO is always the first mux entry
  53         * (b) GPIO's outen is also used to set the pad
  54         the reason for this is that it is assumed better that
  55         multiple pads be switched simutaneously to outputs
  56         by setting the GPIO direction rather than having them
  57         set arbitrarily by changing the muxer registers.
  58     """
  59     idx += 1
  60     if idx < len(cells):
  61         cell = cells[idx]
  62     else:
  63         cell = ''
  64     if not cell:
  65         return 'val0'
  66     temp = transfn(cell)
  67     x = ifaces.getifacetype(temp)
  68     if x == 'input':
  69         return 'val0'  # inputs don't get passed through to the out mux
  70     if suffix == '_outen' and x == 'out':
  71         return "wr%s%s" % (cells[1], suffix or '')  # USE GPIO FOR SELECTION
  72     if x == 'out':  # sigh hack, should be using interface_decl
  73         suffix = ''
  74     return "wr%s%s" % (cell, suffix or '')
  75
  76 # XXX this needs to move into interface_decl.py
  77
  78
  79 def mkcomment(ifaces, cell, idx, outenmode=False):
  80     """ returns a comment string for the cell when muxed
  81     """
  82     idx += 1
  83     if idx >= len(cell):
  84         return ' // unused'
  85     cname = cell[idx]
  86     if not cname:
  87         return ' // unused'
  88     temp = transfn(cname)
  89     x = ifaces.getifacetype(temp)
  90     #print (cname, x)
  91     if x == 'input':
  92         return ' // %s is an input' % cname
  93     if outenmode and x == 'inout':
  94         return ' // bi-directional'
  95     if outenmode and x == 'out':
  96         return ' // %s is an output' % cname
  97
  98     return ""
  99
 100
 101 def mkmux(p, ifaces, cell, suffix, outenmode):
 102     """ creates a straight many-to-one muxer that accepts
 103         multiple inputs and, based on an "address" routes
 104         a given indexed input through to the (one) output
 105     """
 106     comment = 'outen' if outenmode else 'output'
 107     fmtstr = "\t\t\twr%s==%d?%s:%s\n"  # mux-selector format
 108     ret = ''
 109     ret += "      // %s muxer for cell idx %s\n" % (comment, cell[0])
 110     ret += "      %s%s=\n" % (cn(cell[0]), suffix)
 111     for i in range(
 112             0, (1 << p.cell_bitwidth) - 1):  # full mux range (minus 1)
 113         comment = mkcomment(ifaces, cell, i, outenmode)
 114         cf = fmt(ifaces, cell, i, suffix)
 115         ret += fmtstr % (cn(cell[0]), i, cf, comment)
 116     comment = mkcomment(ifaces, cell, i + 1, outenmode)
 117     ret += "\t\t\t" + fmt(ifaces, cell, i + 1, suffix)  # last line
 118     ret += ";%s\n" % comment
 119
 120     return ret
 121
 122
 123 def init(p, ifaces):
 124     """ generates the actual output pinmux for each io-cell.  blank lines
 125         need to output "0" to the iopad, if there is no entry in
 126         that column.
 127
 128         text is outputted in the format:
 129             x_out =
 130                 muxer_sel==0 ? a :
 131                 muxer_sel==1 ? b :
 132                 muxer_sel==2 ? 0 :
 133                 d
 134
 135         last line doesn't need selector-logic, obviously.
 136
 137         note that it's *important* that all muxer options be covered
 138         (hence going up to 1<<cell_bitwidth) even if the muxer cells
 139         are blank (no entries), because muxer selection could be to
 140         the last one, and we do not want the "default" (last line)
 141         to be the output.
 142     """
 143     p.pinmux = ' '
 144     global dedicated_wire
 145     for cell in p.muxed_cells:
 146
 147         # first do the outputs
 148         p.pinmux += mkmux(p, ifaces, cell, '_out', False)
 149         p.pinmux += "\n"
 150
 151         # now do the output enablers (outens)
 152         p.pinmux += mkmux(p, ifaces, cell, '_outen', True)
 153
 154         # ======================================================== #
 155
 156         # check each cell if "peripheral input/inout" then assign its wire
 157         # Here we check the direction of each signal in the dictionary.
 158         # We choose to keep the dictionary within the code and not user-input
 159         # since the interfaces are always standard and cannot change from
 160         # user-to-user. Plus this also reduces human-error as well :)
 161         p.pinmux += "\n"
 162         p.pinmux += "      // priority-in-muxer for cell idx %s\n" % (cell[0])
 163         for i in range(0, len(cell) - 1):
 164             cname = cell[i + 1]
 165             if not cname:  # skip blank entries, no need to test
 166                 continue
 167             temp = transfn(cname)
 168             x = ifaces.getifacetype(temp)
 169             print (cname, temp, x)
 170             assert x is not None, "ERROR: The signal : " + \
 171                 str(cname) + \
 172                 " of pinmap.txt isn't present \nin the current" + \
 173                 " dictionary. Update dictionary or fix-typo."
 174             if x == "input":
 175                 p.pinmux += \
 176                     mux_wire.format(cell[0], i, "wr" + cname) + "\n"
 177             elif x == "inout":
 178                 p.pinmux += \
 179                     mux_wire.format(cell[0], i, "wr" + cname +
 180                                                 "_in") + "\n"
 181     # ============================================================ #
 182
 183     # ==================  Logic for dedicated pins ========= #
 184     p.pinmux += "\n      /*=========================================*/\n"
 185     p.pinmux += "      // dedicated cells\n\n"
 186     for cell in p.dedicated_cells:
 187         p.pinmux += "      // dedicated cell idx %s\n" % (cell[0])
 188         p.pinmux += "      %s_out=%s_io;\n" % (cn(cell[0]), cell[1])
 189         temp = transfn(cell[1])
 190         x = ifaces.getifacetype(temp)
 191         #print cell, temp, x
 192         if x == "input":
 193             p.pinmux += \
 194                 dedicated_wire.format(cell[0], "wr" + cell[1]) + "\n"
 195         elif x == "inout":
 196             p.pinmux += \
 197                 dedicated_wire.format(cell[0], "wr" + cell[1] + "_in") + "\n"
 198         else:
 199             p.pinmux += "\n"
 200     # =======================================================#