vivado の最適化
まずは使われそうにない下位ビットをはっしょった。ほんとうは先に最適化してはいけない。
+-------------------------------------------------------------+----------+-------+-----------+-------+ | Site Type | Used | Fixed | Available | Util% | +-------------------------------------------------------------+----------+-------+-----------+-------+ | Slice | 121 | 0 | 13300 | 0.91 | | SLICEL | 81 | 0 | | | | SLICEM | 40 | 0 | | | | LUT as Logic | 285 | 0 | 53200 | 0.54 | | using O5 output only | 2 | | | | | using O6 output only | 175 | | | | | using O5 and O6 | 108 | | | | | LUT as Memory | 0 | 0 | 17400 | 0.00 | | LUT as Distributed RAM | 0 | 0 | | | | LUT as Shift Register | 0 | 0 | | | | LUT Flip Flop Pairs | 388 | 0 | 53200 | 0.73 | | fully used LUT-FF pairs | 202 | | | | | LUT-FF pairs with unused LUT | 105 | | | | | LUT-FF pairs with unused Flip Flop | 81 | | | | | Unique Control Sets | 20 | | | | | Minimum number of registers lost to control set restriction | 57(Lost) | | | | +-------------------------------------------------------------+----------+-------+-----------+-------+
Yレジの計算をちゃんと 16bit にしたら増えた。
+-------------------------------------------------------------+----------+-------+-----------+-------+ | Site Type | Used | Fixed | Available | Util% | +-------------------------------------------------------------+----------+-------+-----------+-------+ | Slice | 124 | 0 | 13300 | 0.93 | | SLICEL | 84 | 0 | | | | SLICEM | 40 | 0 | | | | LUT as Logic | 298 | 0 | 53200 | 0.56 | | using O5 output only | 2 | | | | | using O6 output only | 197 | | | | | using O5 and O6 | 99 | | | | | LUT as Memory | 0 | 0 | 17400 | 0.00 | | LUT as Distributed RAM | 0 | 0 | | | | LUT as Shift Register | 0 | 0 | | | | LUT Flip Flop Pairs | 410 | 0 | 53200 | 0.77 | | fully used LUT-FF pairs | 209 | | | | | LUT-FF pairs with unused LUT | 114 | | | | | LUT-FF pairs with unused Flip Flop | 87 | | | | | Unique Control Sets | 20 | | | | | Minimum number of registers lost to control set restriction | 50(Lost) | | | | +-------------------------------------------------------------+----------+-------+-----------+-------+
重複しているところを variable にしてみたら変わらず。
どうやらもともと最適化が効いている。苦労して最適化する必要なし。
+-------------------------------------------------------------+----------+-------+-----------+-------+ | Site Type | Used | Fixed | Available | Util% | +-------------------------------------------------------------+----------+-------+-----------+-------+ | Slice | 124 | 0 | 13300 | 0.93 | | SLICEL | 84 | 0 | | | | SLICEM | 40 | 0 | | | | LUT as Logic | 298 | 0 | 53200 | 0.56 | | using O5 output only | 2 | | | | | using O6 output only | 197 | | | | | using O5 and O6 | 99 | | | | | LUT as Memory | 0 | 0 | 17400 | 0.00 | | LUT as Distributed RAM | 0 | 0 | | | | LUT as Shift Register | 0 | 0 | | | | LUT Flip Flop Pairs | 410 | 0 | 53200 | 0.77 | | fully used LUT-FF pairs | 209 | | | | | LUT-FF pairs with unused LUT | 114 | | | | | LUT-FF pairs with unused Flip Flop | 87 | | | | | Unique Control Sets | 20 | | | | | Minimum number of registers lost to control set restriction | 50(Lost) | | | | +-------------------------------------------------------------+----------+-------+-----------+-------+
