Using Auto-Restart in Cosimulation (C/RTL Cosim) - Using Auto-Restart in Cosimulation (C/RTL Cosim) - 2026.1 English - UG1399

Vitis High-Level Synthesis User Guide (UG1399)

Document ID
UG1399
Release Date
2026-06-23
Version
2026.1 English

Auto-Restart enables a kernel/IP to re-launch itself immediately after each completion for a finite number of iterations, without software intervention or gaps. In the traditional co-simulation flow with AXI4-Lite that does not use the autorestart feature, the cosim framework creates 4 cycle gaps between successive DUT launches to perform the ap_ctrl_hs handshake using AXI4-Lite transactions, preventing a seamless no-gap execution for DUTs with a low initiation interval (II <= 5) at the top.

The Auto-Restart helper class eliminates startup gaps during co-simulation (cosim), ensuring continuous, gap-free kernel execution for the specified number of iterations.