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     cellnum = cell[0]
 107     comment = 'outen' if outenmode else 'output'
 108     fmtstr = "\t\t\twr%s==%d?%s:%s\n"  # mux-selector format
 109     ret = ''
 110     ret += "      // %s muxer for cell idx %s\n" % (comment, cellnum)
 111     ret += "      %s%s=\n" % (cn(cellnum), suffix)
 112     i = 0
 113     for i in range(
 114             0, p.get_muxwidth(cellnum) - 1):  # full mux range (minus 1)
 115         comment = mkcomment(ifaces, cell, i, outenmode)
 116         cf = fmt(ifaces, cell, i, suffix)
 117         ret += fmtstr % (cn(cell[0]), i, cf, comment)
 118     comment = mkcomment(ifaces, cell, i + 1, outenmode)
 119     ret += "\t\t\t" + fmt(ifaces, cell, i + 1, suffix)  # last line
 120     ret += ";%s\n" % comment
 121
 122     return ret
 123
 124
 125 def init(p, ifaces):
 126     """ generates the actual output pinmux for each io-cell.  blank lines
 127         need to output "0" to the iopad, if there is no entry in
 128         that column.
 129
 130         text is outputted in the format:
 131             x_out =
 132                 muxer_sel==0 ? a :
 133                 muxer_sel==1 ? b :
 134                 muxer_sel==2 ? 0 :
 135                 d
 136
 137         last line doesn't need selector-logic, obviously.
 138
 139         note that it's *important* that all muxer options be covered
 140         (hence going up to 1<<cell_bitwidth) even if the muxer cells
 141         are blank (no entries), because muxer selection could be to
 142         the last one, and we do not want the "default" (last line)
 143         to be the output.
 144     """
 145     p.pinmux = ' '
 146     global dedicated_wire
 147     for cell in p.muxed_cells:
 148
 149         # first do the outputs
 150         p.pinmux += mkmux(p, ifaces, cell, '_out', False)
 151         p.pinmux += "\n"
 152
 153         # now do the output enablers (outens)
 154         p.pinmux += mkmux(p, ifaces, cell, '_outen', True)
 155
 156         # ======================================================== #
 157
 158         # check each cell if "peripheral input/inout" then assign its wire
 159         # Here we check the direction of each signal in the dictionary.
 160         # We choose to keep the dictionary within the code and not user-input
 161         # since the interfaces are always standard and cannot change from
 162         # user-to-user. Plus this also reduces human-error as well :)
 163         p.pinmux += "\n"
 164         p.pinmux += "      // priority-in-muxer for cell idx %s\n" % (cell[0])
 165         for i in range(0, len(cell) - 1):
 166             cname = cell[i + 1]
 167             if not cname:  # skip blank entries, no need to test
 168                 continue
 169             temp = transfn(cname)
 170             x = ifaces.getifacetype(temp)
 171             print (cname, temp, x)
 172             assert x is not None, "ERROR: The signal : " + \
 173                 str(cname) + \
 174                 " of pinmap.txt isn't present \nin the current" + \
 175                 " dictionary. Update dictionary or fix-typo."
 176             if x == "input":
 177                 p.pinmux += \
 178                     mux_wire.format(cell[0], i, "wr" + cname) + "\n"
 179             elif x == "inout":
 180                 p.pinmux += \
 181                     mux_wire.format(cell[0], i, "wr" + cname +
 182                                                 "_in") + "\n"
 183     # ============================================================ #
 184
 185     # ==================  Logic for dedicated pins ========= #
 186     p.pinmux += "\n      /*=========================================*/\n"
 187     p.pinmux += "      // dedicated cells\n\n"
 188     for cell in p.dedicated_cells:
 189         p.pinmux += "      // dedicated cell idx %s\n" % (cell[0])
 190         p.pinmux += "      %s_out=%s_io;\n" % (cn(cell[0]), cell[1])
 191         temp = transfn(cell[1])
 192         x = ifaces.getifacetype(temp)
 193         #print cell, temp, x
 194         if x == "input":
 195             p.pinmux += \
 196                 dedicated_wire.format(cell[0], "wr" + cell[1]) + "\n"
 197         elif x == "inout":
 198             p.pinmux += \
 199                 dedicated_wire.format(cell[0], "wr" + cell[1] + "_in") + "\n"
 200         else:
 201             p.pinmux += "\n"
 202     # =======================================================#