lib/python/flatspice.py

   1 # flatspice.py
   2 #-----------------------------------------------------------
   3 # Python script which writes a SPICE-format netlist.
   4 # Replaces the code formerly in "netlist.c" (deprecated).
   5 # Python scripting is now the preferred method for handling
   6 # netlist output formats.
   7 #-----------------------------------------------------------
   8
   9 # Select the device string corresponding to the given prefix.
  10 # Return the body of the string, or an empty string if the prefix doesn't match.
  11
  12 def select(sstr, prefix):
  13    ltext = ''
  14    if sstr.startswith(prefix):
  15       ltext += sstr[len(prefix) + 1:]
  16    return ltext
  17
  18 # Generate an ASCII string from an xcircuit string (list)
  19
  20 def textprint(slist, params):
  21    ltext = ''
  22    is_symbol = 0
  23    is_iso = 0
  24    for x in slist:
  25       try:
  26         f = x.keys()[0]
  27       except AttributeError:            # must be a string
  28         if x == 'Return':
  29            ltext += '\n'
  30         elif x == 'Underline':
  31            ltext += '_'
  32         elif x == 'Overline':
  33            ltext += '!'
  34       else:                     # is a dictionary; will have only one key
  35         if f == 'Font':
  36            lfont = x[x.keys()[0]]
  37            if lfont.startswith('Symbol'):
  38               is_symbol = 1
  39            else:
  40               is_symbol = 0
  41            if lfont.endswith('ISO'):
  42               is_iso = 1
  43            else:
  44               is_iso = 0
  45         elif f == 'Parameter':
  46            ltext += textprint(params[x[x.keys()[0]]], [])
  47         else:                           # text:  SPICE translates "mu" to "u"
  48            for y in x[x.keys()[0]]:
  49               if is_symbol:
  50                  if y == 'f':
  51                     ltext += 'phi'
  52                  elif y == 'm':
  53                     ltext += 'u'
  54                  else:
  55                     ltext += y
  56               else:
  57                  if ord(y) == 181:
  58                     ltext += 'u'
  59                  elif ord(y) > 127:
  60                     ltext += '/' + str(ord(y))
  61                  else:
  62                     ltext += y
  63    return ltext
  64
  65
  66 # Flatten the netlist and write to the output
  67
  68 def recurseflat(outfile, ckt, clist):
  69    try:
  70       v = ckt['calls']          # calls to subcircuits
  71    except KeyError:             # A bottom-level circuit element
  72       pass
  73    else:
  74       for y in v:
  75          for z in clist:
  76             if z['name'] == y['name']:
  77                # copy the object and substitute net names into subcircuit ports
  78                lobj = z
  79                lobj['ports'] = y['ports']
  80                recurseflat(outfile, lobj, clist)
  81                break;
  82    try:
  83       w = ckt['devices']
  84    except KeyError:
  85       pass
  86    else:
  87       for y in w:
  88          for u in y:
  89             lstr = select(textprint(u, []), 'spice')
  90             if lstr <> '':
  91                outfile.write('device: ' + lstr + '\n')
  92
  93 # Top of the flattened-circuit writing routine
  94
  95 def writespiceflat():
  96    p=netlist()
  97    g=p['globals']
  98    c=p['circuit']
  99    l=len(c)
 100    top=c[l-1]
 101    topname=top['name']
 102    topname += '.spc'
 103    try:
 104       outfile=open(topname, 'w')
 105    except IOError:
 106       return
 107
 108    # print header line
 109
 110    outfile.write('*SPICE flattened circuit "' + topname + '"')
 111    outfile.write(' from XCircuit v' + str(xc_version))
 112    outfile.write(' (Python script "flatspice.py")\n')
 113
 114    # print global variables
 115
 116    for x in g:  # 'globals' is a list of strings
 117       outfile.write('.GLOBAL ' + textprint(x, []) + '\n')
 118    outfile.write('\n')
 119
 120    recurseflat(outfile, top, c)
 121    outfile.write('.end\n')
 122    outfile.close()
 123
 124 # Key binding and menu button for the spice netlist output
 125 # bind('Alt_F', 'writespiceflat')
 126 newbutton('Netlist', 'Write Flattened Spice', 'writespiceflat')
 127