module fpenc 
title 'Fixed-point to Floating-point Encoder 
J. Wakerly, Xanthrax Systems' 
" FPENC device 'P20L8'; 

" Input and output pins 
B10..B0                      pin 1..11;
E2..E0, M3..M0               pin 21..15 istype 'com';

" Constant expressions 
B = [B10..B0];
E = [E2..E0];
M = [M3..M0];

equations

WHEN B < 16 THEN E = 0;
ELSE WHEN B < 32 THEN E = 1;
ELSE WHEN B < 64 THEN E = 2;
ELSE WHEN B < 128 THEN E = 3;
ELSE WHEN B < 256 THEN E = 4;
ELSE WHEN B < 512 THEN E = 5;
ELSE WHEN B < 1024 THEN E = 6;
ELSE E = 7;

M = (E==0) & [B3..B0]
  # (E==1) & [B4..B1]
  # (E==2) & [B5..B2]
  # (E==3) & [B6..B3]
  # (E==4) & [B7..B4]
  # (E==5) & [B8..B5]
  # (E==6) & [B9..B6]
  # (E==7) & [B10..B7];

end fpenc