SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
This section reviews various hardware resources of the channel controller that are programmed from the ARP32 controller of the EVE subsystem.
Parameter set: A parameter set is the program memory of the channel controller that describes the attributes of a transfer. Each parameter set describes one data transfer from a source address to a destination address. A parameter set is a group of eight contiguous 32-bit words and has an address that is aligned on a 256-bit boundary. There are 64 of these parameter sets, allowing the description of 64 transfers ahead of time. Individual parameter sets are used to describe isolated transfers, or they are linked together to describe a group of related transfers.
There are two types of DMA channels in the channel controller (CC) interface:
An EDMA channel is used to describe a regular sequence of data transfers, in which the amount of data sent or received, and source and destination data address increments between successive transfers does not vary dynamically, but by regular amounts. A QDMA channel is used when it is needed to program in new values for the source and destination addresses. The amount of data to transferred varies from one transfer to another, and for other dynamic situations.
EVENT queue: data transfer events are different physical DMA channels (ESR writes for EDMA channels and parameter set trigger word writes for QDMA channels) and are detected simultaneously. The events are queued based on a fixed priority arbitration scheme; the EDMA channels are higher-priority events than the QDMA channels. Among the two groups of channels, the lowest-numbered channel is the highest priority.
Figure 8-12 shows the block diagram of the channel controller.