Cyclone® V Device Handbook: Volume 1: Device Interfaces and Integration

ID 683375
Date 10/18/2023
Public
Document Table of Contents

7.8.2. Evaluating Data Setup and Hold Timing Slack in AS Configuration

Follow the guideline below to evaluate and ensure the setup time, tDSU and hold time, tDH meets the requirements explained in the Cyclone® V device datasheets. While evaluating the tDSU and tDH slack in your system, you can also use the equations to estimate the trace length for the DCLK and DATA[3..0] lines on your system.

Figure 154. FPGA to EPCQ-A Board Trace Block Diagram

The data setup timing slack must be equal or larger than the minimum data setup time, tDSU

tDCLK – (tBT_DCLK + tCLQV + tBT_DATA) ≥ tDSU

The hold timing slack must be equal or larger than the minimum data hold time, tDH:

tBT_DCLK + tCLQX + tBT_DATA ≥ tDH

  • tDCLK = Period for a DCLK cycle
  • tBT_DCLK = Board trace propagation delay for DCLK from FPGA to EPCQ-A
  • tCLQV = Clock low to output valid
  • tCLQX = Output hold time
  • tBT_DATA = Board trace propagation delay for Data from EPCQ-A to FPGA
  • tDSU = Minimum data setup time required by FPGA
  • tDH = Minimum data hold time required by FPGA