Reference
Dense, bookmarkable cheatsheets — the stuff you keep looking up.
AXI4 / AXI-Lite / AXI-Stream Cheatsheet
The signals, the handshake rules, and the mistakes everyone makes once.
FPGA Part Number Decoder
What all those letters and digits on the chip actually mean.
Quartus SDC Constraints Cheatsheet
Timing constraints for Intel/Altera FPGAs — same TCL dialect, different details.
Verilog / SystemVerilog Quick Reference
The constructs you actually use in synthesizable RTL, in one page.
VHDL Quick Reference
Synthesizable VHDL-2008 patterns without the boilerplate archaeology.
Vivado XDC Constraints Cheatsheet
The dozen constraint lines that cover 95% of Artix/Kintex/Zynq designs.