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         The exception to this rule is when the muxer width is 1
  60         (i.e. it is a dedicated line).  Then, a "1" is outputted
  61         and the pin is PERMANENTly enabled as an output.
  62     """
  63     idx += 1
  64     if idx < len(cells):
  65         cell = cells[idx]
  66     else:
  67         cell = ''
  68     #print "fmt", idx, cells, cell
  69     if not cell:
  70         return 'val0'
  71     temp = transfn(cell)
  72     x = ifaces.getifacetype(temp)
  73     if x == 'input':
  74         return 'val0'  # inputs don't get passed through to the out mux
  75     if suffix == '_outen' and x == 'out':
  76         if len(cells) == 2:
  77             return "val1"
  78         return "wr%s%s" % (cells[1], suffix or '')  # USE GPIO FOR SELECTION
  79     if x == 'out':  # sigh hack, should be using interface_decl
  80         suffix = ''
  81     return "wr%s%s" % (cell, suffix or '')
  82
  83 # XXX this needs to move into interface_decl.py
  84
  85
  86 def mkcomment(ifaces, cell, idx, outenmode=False):
  87     """ returns a comment string for the cell when muxed
  88     """
  89     idx += 1
  90     if idx >= len(cell):
  91         return ' // unused'
  92     cname = cell[idx]
  93     if not cname:
  94         return ' // unused'
  95     temp = transfn(cname)
  96     x = ifaces.getifacetype(temp)
  97     #print (cname, x)
  98     if x == 'input':
  99         return ' // %s is an input' % cname
 100     if outenmode and x == 'inout':
 101         return ' // bi-directional'
 102     if outenmode and x == 'out':
 103         return ' // %s is an output' % cname
 104
 105     return ""
 106
 107
 108 def mkmux(p, ifaces, cell, suffix, outenmode):
 109     """ creates a straight many-to-one muxer that accepts
 110         multiple inputs and, based on an "address" routes
 111         a given indexed input through to the (one) output
 112     """
 113     cellnum = cell[0]
 114     comment = 'outen' if outenmode else 'output'
 115     fmtstr = "\t\t\twr%s==%d?%s:%s\n"  # mux-selector format
 116     ret = ''
 117     ret += "      // %s muxer for cell idx %s\n" % (comment, cellnum)
 118     ret += "      %s%s=\n" % (cn(cellnum), suffix)
 119     i = 0
 120     mwid = p.get_muxwidth(cellnum)
 121     if mwid > 1:
 122         for i in range(0, mwid - 1):  # full mux range (minus 1)
 123             comment = mkcomment(ifaces, cell, i, outenmode)
 124             cf = fmt(ifaces, cell, i, suffix)
 125             ret += fmtstr % (cn(cell[0]), i, cf, comment)
 126         i += 1
 127     comment = mkcomment(ifaces, cell, i, outenmode)
 128     ret += "\t\t\t" + fmt(ifaces, cell, i, suffix)  # last line
 129     ret += ";%s\n" % comment
 130
 131     return ret
 132
 133
 134 def init(p, ifaces):
 135     """ generates the actual output pinmux for each io-cell.  blank lines
 136         need to output "0" to the iopad, if there is no entry in
 137         that column.
 138
 139         text is outputted in the format:
 140
 141         x_out =
 142             muxer_sel==0 ? a :
 143             muxer_sel==1 ? b :
 144             muxer_sel==2 ? 0 :
 145             d
 146
 147         last line doesn't need selector-logic, obviously.
 148
 149         note that it's *important* that all muxer options be covered
 150         (hence going up to 1<<cell_bitwidth) even if the muxer cells
 151         are blank (no entries), because muxer selection could be to
 152         the last one, and we do not want the "default" (last line)
 153         to be the output.
 154     """
 155     p.pinmux = ' '
 156     global dedicated_wire
 157     for cell in p.muxed_cells:
 158
 159         cellidx = cell[0]
 160
 161         p.pinmux += "      // --------------------\n"
 162         p.pinmux += "      // ----- cell %s -----\n\n" % (cellidx)
 163
 164         # first do the outputs
 165         p.pinmux += mkmux(p, ifaces, cell, '_out', False)
 166         p.pinmux += "\n"
 167
 168         # now do the output enablers (outens)
 169         p.pinmux += mkmux(p, ifaces, cell, '_outen', True)
 170
 171         # ======================================================== #
 172
 173         # check each cell if "peripheral input/inout" then assign its wire
 174         # Here we check the direction of each signal in the dictionary.
 175         # We choose to keep the dictionary within the code and not user-input
 176         # since the interfaces are always standard and cannot change from
 177         # user-to-user. Plus this also reduces human-error as well :)
 178         p.pinmux += "\n"
 179         p.pinmux += "      // priority-in-muxer for cell idx %s\n" % (cellidx)
 180         for i in range(0, len(cell) - 1):
 181             cname = cell[i + 1]
 182             if not cname:  # skip blank entries, no need to test
 183                 continue
 184             temp = transfn(cname)
 185             x = ifaces.getifacetype(temp)
 186             print (cname, temp, x)
 187             assert x is not None, "ERROR: The signal : " + \
 188                 str(cname) + \
 189                 " of pinmap.txt isn't present \nin the current" + \
 190                 " dictionary. Update dictionary or fix-typo."
 191             bwid = p.get_muxbitwidth(cellidx)
 192             if bwid > 0:
 193                 muxcell(p, cname, x, cell, i)
 194             else:
 195                 dedcell(p, x, cell)
 196
 197     # ==================  Logic for dedicated pins ========= #
 198     p.pinmux += "\n      /*=========================================*/\n"
 199     p.pinmux += "      // dedicated cells\n\n"
 200     for cell in p.dedicated_cells:
 201         p.pinmux += "      // dedicated cell idx %s\n" % (cell[0])
 202         p.pinmux += "      %s_out=%s_io;\n" % (cn(cell[0]), cell[1])
 203         temp = transfn(cell[1])
 204         x = ifaces.getifacetype(temp)
 205         #print cell, temp, x
 206         dedcell(p, x, cell)
 207
 208
 209 def muxcell(p, cname, x, cell, i):
 210     if x == "input":
 211         p.pinmux += \
 212             mux_wire.format(cell[0], i, "wr" + cname) + "\n"
 213     elif x == "inout":
 214         p.pinmux += \
 215             mux_wire.format(cell[0], i, "wr" + cname +
 216                                         "_in") + "\n"
 217
 218
 219 def dedcell(p, x, cell):
 220     if x == "input":
 221         p.pinmux += \
 222             dedicated_wire.format(cell[0], "wr" + cell[1]) + "\n"
 223     elif x == "inout":
 224         p.pinmux += \
 225             dedicated_wire.format(cell[0], "wr" + cell[1] + "_in") + "\n"