SPRUJ79 November 2024 F29H850TU
RTDMA is connected through a slow access port as shown in Figure 3-18, so all accesses are minimum one wait state. To improve throughput, RTDMA supports local address generation within the MEMSS memory controller. This enables performance close to zero wait states.
Local address generation within a burst is enabled by the following signals:
Without burst signaling, the address is latched first and then presented to memory. With burst, this happens only once for the first access, since the MEMSS memory controller does not use addresses generated by the RTDMA for subsequent accesses, as addresses is generated locally.
The LAST signal is an indication to stop the lookahead read. If the LAST signal is not generated, the RTDMA request going inactive is treated as a burst termination.
The RTDMA arbitration is locked when the FIRST access of a burst is granted, and the arbitration is released on the LAST access. Accesses with the FIRST and LAST signals asserted are treated as non-burst, and a lookahead read is not initiated nor is the arbitration locked. The arbitration lock is removed if the RTDMA channel is halted due to a CPU halt.