Three-State Buffers
Each CLB is associated with two Three-State Buffers (BUFT)
- BUFTs are used independently of LUTs and Flip-Flops
Three-State library components:
- Three-State Buffers: BUFT, BUFT4, BUFT8, BUFT16
- Wired-AND (open Drain) : WAND1, WAND4, WAND8, WAND16
- Two input OR driving Wired-AND : WOR2AND
Delay varies per family
- 3.7 ns in the XC4005XL (-1)
- 13.6 ns in the XC4085XL (-1)