scripts init

scripts/gen_deinter_lut.py

@@ -0,0 +1,225 @@
+#!/usr/bin/env python
+
+"""
+Generate 802.11a/g/n Deinterleave LUT.
+
+Output compensate for pucntureing.
+
+"""
+
+import argparse
+import math
+import decode
+import os
+
+"""
+LUT ENTRY FORMAT
+
+
+1 bit -- null_a
+1 bit -- null_b
+6 bit -- addra
+6 bit -- addrb
+3 bit -- bita
+3 bit -- bitb
+1 bit -- out_stb
+1 bit -- done
+-------------------
+22 bits total
+
+
+LUT FORMAT
+
++----------------+
+|  BASE ADDR     |
+|   32 ENTRY     |
++----------------+
+|   6 MBPS       |
++----------------+
+|   9 MBPS       |
++----------------+
+ ....
++----------------+
+|   MCS 0        |
++----------------+
+ ...
++----------------+
+|   MCS 7        |
++----------------+
+|   PADDING      |
++----------------+
+"""
+
+RATE_BITS = {
+    6: '1011',
+    9: '1111',
+    12: '1010',
+    18: '1110',
+    24: '1001',
+    36: '1101',
+    48: '1000',
+    54: '1100',
+}
+
+
+RATES = [
+    # (rate, mcs, ht)
+    (6, 0, False),
+    (9, 0, False),
+    (12, 0, False),
+    (18, 0, False),
+    (24, 0, False),
+    (36, 0, False),
+    (48, 0, False),
+    (54, 0, False),
+
+    (0, 0, True),
+    (0, 1, True),
+    (0, 2, True),
+    (0, 3, True),
+    (0, 4, True),
+    (0, 5, True),
+    (0, 6, True),
+    (0, 7, True),
+]
+
+
+def do_rate(rate=6, mcs=0, ht=False):
+    idx_map = decode.Decoder(None).deinterleave(None, rate=rate, mcs=mcs, ht=ht)
+    seq = [t[1] for t in idx_map]
+
+    erase = '1/2'
+
+    if ht:
+        n_bpsc = decode.HT_MCS_PARAMETERS[mcs][0]
+        if mcs in [2, 4, 6]:
+            erase = '3/4'
+            pass
+        elif mcs == 5:
+            erase = '2/3'
+            pass
+        elif mcs == 7:
+            erase = '5/6'
+    else:
+        n_bpsc = decode.RATE_PARAMETERS[rate][0]
+        if rate in [9, 18, 36]:
+            erase = '3/4'
+        elif rate == 48:
+            erase = '2/3'
+
+    data = []
+
+    i = 0
+    puncture = 0
+    while i < len(seq):
+        addra = seq[i]/n_bpsc
+        bita = seq[i]%n_bpsc
+        if i+1 < len(seq):
+            addrb = seq[i+1]/n_bpsc
+            bitb = seq[i+1]%n_bpsc
+        else:
+            addrb = 0
+            bitb = 0
+
+        base = (addra<<14) + (addrb<<8) + (bita<<5) + (bitb<<2) + (1<<1)
+
+        if erase == '1/2':
+            mask = base
+            data.append(mask)
+        elif erase == '3/4':
+            if puncture == 0:
+                mask = base
+                data.append(mask)
+                puncture = 1
+            else:
+                mask = (1<<20) + base
+                data.append(mask)
+                mask = (1<<21) + base
+                data.append(mask)
+                puncture = 0
+        elif erase == '2/3':
+            if puncture == 0:
+                mask = base
+                data.append(mask)
+                puncture = 1
+            else:
+                mask = (1<<20) + base
+                data.append(mask)
+                i -= 1
+                puncture = 0
+        elif erase == '5/6':
+            if puncture == 0:
+                mask = base
+                data.append(mask)
+                puncture = 1
+            elif puncture == 1:
+                mask = (1<<20) + base
+                data.append(mask)
+                mask = (1<<21) + base
+                data.append(mask)
+                puncture = 2
+            else:
+                mask = (1<<20) + base
+                data.append(mask)
+                mask = (1<<21) + base
+                data.append(mask)
+                puncture = 0
+        i += 2
+
+    # reset addra to NUM_SUBCARRIER/2
+    if ht:
+        mask = (26<<14) + 1
+    else:
+        mask = (24<<14) + 1
+    data.append(mask)
+
+    # sentinel
+    data.extend([0]*4)
+
+    return data
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--out')
+    args = parser.parse_args()
+
+    if args.out is None:
+        args.out = os.path.join(os.getcwd(), 'deinter_lut.mif')
+
+    coe_out = '%s.coe' % (os.path.splitext(args.out)[0])
+
+    header = [0]*32
+    lut = []
+    offset = 32
+    for rate, mcs, ht in RATES:
+        if ht:
+            idx = (1<<4) + mcs
+        else:
+            idx = int(RATE_BITS[rate], 2)
+        header[idx] = offset
+        print '[rate=%d, mcs=%d] -> %d' % (rate, mcs, offset)
+
+        data = do_rate(rate=rate, mcs=mcs, ht=ht)
+        offset += len(data)
+        lut.extend(data)
+
+    total = int(2**math.ceil(math.log(offset, 2)))
+    print 'Total row: %d (round up to %d)' % (offset, total)
+
+    lut.extend([0]*(total-offset))
+
+    with open(args.out, 'w') as f:
+        for l in header + lut:
+            f.write('{0:022b}\n'.format(l))
+    print "MIL file saved as %s" % (args.out)
+
+    with open(coe_out, 'w') as f:
+        f.write('memory_initialization_radix=2;\n')
+        f.write('memory_initialization_vector=\n')
+        f.write(',\n'.join(['{0:022b}'.format(l) for l in header+lut]))
+        f.write(';')
+    print "COE file saved as %s" % (coe_out)
+
+if __name__ == '__main__':
+    main()