Some embodiments relate to a Direct Memory Access (DMA) controller. The DMA controller includes a bus controller having a system bus interface and configured to read a pattern from a memory location via the system bus interface. Pattern comparison logic compares the read pattern to at least one predetermined pattern. Control logic induces the bus controller to process a first conditional link over the system bus interface if the read pattern differs from the predetermined pattern, and induces the bus controller to process a second conditional link over the system bus interface if the read pattern differs from the predetermined pattern.