Intel® FPGA SDK for OpenCL™ Pro Edition: Programming Guide

ID 683846
Date 10/04/2021
Public

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11.1.2.6.1. Intel® Stratix® 10 Design-Specific Reset Requirements for Stall-Free and Stallable RTL Modules

When creating an RTL module for Intel® Stratix® 10 OpenCL designs, ensure that the module satisfies specific logic reset requirements.

Reset Requirements for Stall-Free RTL Modules

A stall-free RTL module is a fixed-latency module for which the Intel® FPGA SDK for OpenCL™ Offline Compiler can optimize away stall logic.

  • When creating a stall-free RTL module for a Intel® Stratix® 10 design, use synchronous clear signals only.
  • After deassertion of the reset signal to the stall-free RTL module, the module must be operational within 15 clock cycles. If the reset signal is pipelined within the module, this requirement limits the reset pipelining to no more than 15 stages.

Reset Requirements for Stallable RTL Modules

A stallable RTL module has a variable latency, and it relies on backpressured input and output interfaces to function correctly.

  • When creating a stallable RTL module for a Intel® Stratix® 10 design, use synchronous clear signals only.
  • After assertion of the reset signal to the stallable RTL module, the module must deassert its oready and ovalid interface signals within 40 clock cycles.
  • After deassertion of the reset signal to the stallable RTL module, the module must be fully operational within 40 clock cycles. The module signals its readiness by asserting the oready interface signal.