Read: get channel DREQ counter (i.e. how many accesses the DMA expects it can perform on the peripheral without overflow/underflow. Write any value: clears the counter, and cause channel to re-initiate DREQ handshake.
The number of channels this DMA instance is equipped with. This DMA supports up to 16 hardware channels, but can be configured with as few as one, to minimise silicon area.
Security configuration for channel 0. Control whether this channel performs Secure/Non-secure and Privileged/Unprivileged bus accesses. If this channel generates bus accesses of some security level, an access of at least that level (in the order S+P > S+U > NS+P > NS+U) is required to program, trigger, abort, check the status of, interrupt on or acknowledge the interrupt of this channel. This register automatically locks down (becomes read-only) once software starts to configure the channel. This register is world-readable, but is writable only from a Secure, Privileged context.
Security configuration for IRQ 0. Control whether the IRQ permits configuration by Non-secure/Unprivileged contexts, and whether it can observe Secure/Privileged channel interrupt flags.
Pacing (X/Y) fractional timer The pacing timer produces TREQ assertions at a rate set by ((X/Y) * sys_clk). This equation is evaluated every sys_clk cycles and therefore can only generate TREQs at a rate of 1 per sys_clk (i.e. permanent TREQ) or less.