An AXI request can be poisoned by adding poison attribute signals on AxUSER and then passing the poisoned request to a connected AXI slave. When the destination slave (for example, a DDR memory interface port) receives a poisoned request, it handles the request with a write-ignore/read-all-zero (WI/RAZ) response, and, optionally generates a DECERR. Only the DDR_XMPU and OCM_XMPU support poison attribute signals.