I/O Style - OD    - OpenDrain
          - PU    - Pullup
          - PN    - Pulldown
          - KPR   - Keeper
          - S     - SchmittTrigger
          - DG    - DataGate
Reg Use   - LATCH - Transparent latch
          - DFF   - D-flip-flop
          - DEFF  - D-flip-flop with clock enable
          - TFF   - T-flip-flop
          - TDFF  - Dual-edge-triggered T-flip-flop
          - DDFF  - Dual-edge-triggered flip-flop
          - DDEFF - Dual-edge-triggered flip-flop with clock enable
          /S (after any above flop/latch type) indicates initial state is Set