tri fpga-txhold: setup and hold from the routed SDF

Smallest hold 3445 ps on TXD1 against a 1000 ps bench; each TX pin's setup and hold from nextpnr's own SDF of the routed node.

tri fpga-txhold

  ok   ~/openxc7-src/chipdb/xc7a200tfbg484-2.bin 5c88a26d973bff2f                                       
  ok   /tmp/trinet-node-build/e3z/node.json 3b91491691a17672                                            
  ok   /tmp/trinet-node-build/e3z/node.fasm 95809a97d96c563e                                            
  ok   /tmp/trinet-node-build/e3z/src/eth_arp_icmp_ax7203.xdc 8921492b31f5e34f                          
  ok   ~/trinity-fpga/specs/fpga/constraints/eth_arp_icmp_ax7203.xdc 8921492b31f5e34f                   
nextpnr: ~/openxc7-src/nextpnr-xilinx-zinv/build/nextpnr-xilinx --chipdb ~/openxc7-src/chipdb/xc7a200tfb
g484-2.bin --xdc /tmp/trinet-node-build/e3z/src/eth_arp_icmp_ax7203.xdc --json /tmp/trinet-node-build/e3
z/node.json --write /tmp/e3txhold/node_routed.json --fasm /tmp/e3txhold/node.fasm --sdf /tmp/e3txhold/e3
z.sdf --freq 50.0 --seed 1 --placer heap --router router1 --timing-allow-fail                           
nextpnr: exit 0, 151.2 s, log /tmp/e3txhold/nextpnr.log                                                 
fasm: 95809a97d96c563e = e3z                                                                            
sdf: /tmp/e3txhold/e3z.sdf b429acfb8b371e32, 3574156 bytes                                              
sdf: 13392 interconnects, 9453 cell arcs, 4393 cells                                                    
clock: all seven flip-flops from u_rxc_bufg; tq_n on the falling edge, the rest rising                  
TXC C_fall (via tq_p, pin A5): 3222.0 ps  (clock 1184.0, clk-to-Q 100.0, route 1814.0, LUT 124.0)       
TXC C_rise (via tq_n, pin A3): 3072.0 ps  (clock 1184.0, clk-to-Q 100.0, route 1664.0, LUT 124.0)       
eth_txd[0]  D   7732.0 ps over 10 LUTs (clock 1184.0, clk-to-Q 100.0, LUTs 1240.0, routes 5208.0); hold_
fall   4510.0 >= 1000; setup_rise  11340.0 >= 1000                                                      
eth_txd[1]  D   6667.0 ps over 10 LUTs (clock 1184.0, clk-to-Q 100.0, LUTs 1240.0, routes 4143.0); hold_
fall   3445.0 >= 1000; setup_rise  12405.0 >= 1000                                                      
eth_txd[2]  D   8072.0 ps over 10 LUTs (clock 1184.0, clk-to-Q 100.0, LUTs 1240.0, routes 5548.0); hold_
fall   4850.0 >= 1000; setup_rise  11000.0 >= 1000                                                      
eth_txd[3]  D   8025.0 ps over 10 LUTs (clock 1184.0, clk-to-Q 100.0, LUTs 1240.0, routes 5501.0); hold_
fall   4803.0 >= 1000; setup_rise  11047.0 >= 1000                                                      
eth_txctl   D   7370.0 ps over 10 LUTs (clock 1184.0, clk-to-Q 100.0, LUTs 1240.0, routes 4846.0); hold_
fall   4148.0 >= 1000; setup_rise  11702.0 >= 1000                                                      
guess (information only): hold_fall in [2000, 10000] ps on 5/5 pins                                     
smallest hold_fall 3445.0 ps on eth_txd[1]; the bench stands in 3000 ps for the chain                   
VERDICT: PASS                                                                                           
txhold-cast $

recorded 2026-10-07 19:59 UTCreal 2.4 sshown 2.4 sexit codes 0

$ tri fpga-txhold

Staged: the prompt and the typing. Real: every byte the commands printed, at the time they printed it. Any silence longer than 2 s is shown for 2 s, and the title bar says so while it happens. Edited: home directory shown as ~.

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