Cyclone® V Hard Processor System Technical Reference Manual

ID 683126
Date 8/28/2023
Public
Document Table of Contents

26.3.8. Software Reset

Software initialization is done by setting the Init bit in the CAN control register (CCTRL) in the protocol group (protogrp) in the CAN controller register map. This bit is set through the CAN protocol when a bus off condition occurs on the CAN link. The bit is also set through the hardware reset input described in Hardware Reset.

Due to the synchronization mechanism between the two clock domains, there might be a delay until the value written to the Init bit can be read back. To assure that the previous value written has been accepted, read the Init bit before setting it to a new value.

The bus off recovery sequence cannot be shortened by setting or resetting the Init bit. For more information about bus off, refer to the CAN Protocol Specification 2.0 parts A and B, available from the Bosch website.