Enhanced Direct Memory Access (eDMA)
MPC5510 Microcontroller Family Reference Manual, Rev. 1
Freescale Semiconductor
12-3
Preliminary
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Channel completion reported via optional interrupt requests
— One interrupt per channel, optionally asserted at completion of major iteration count
— Error terminations are optionally enabled per channel and logically summed together to form
a single error interrupt.
•
Support for scatter-gather DMA processing
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Any channel can be programmed to be suspended by a higher priority channel’s activation, before
completion of a minor loop.
12.1.3
Modes of Operation
There are two main operating modes of eDMA: normal mode and debug mode. These modes are briefly
described in this section.
12.1.3.1
Normal Mode
In normal mode, the eDMA is used to transfer data between a source and a destination. The source and
destination can be a memory block or an I/O block capable of operation with the eDMA.
12.1.3.2
Debug Mode
In debug mode, the eDMA will not accept new transfer requests when its debug input signal is asserted. If
the signal is asserted during transfer of a block of data described by a minor loop in the current active
channel’s TCD, the eDMA will continue operation until completion of the minor loop.
12.2
External Signal Description
The eDMA has no external signals.
12.3
Memory Map and Registers
This section provides a detailed description of all eDMA registers.
12.3.1
Module Memory Map
The eDMA memory map is shown in
. The address of each register is given as an offset to the
eDMA base address. Registers are listed in address order, identified by complete name and mnemonic, and
list the type of accesses allowed.
shows a graphical representation of the same memory map.
The eDMA’s programming model is partitioned into two regions: the first region defines a number of
registers providing control functions; however, the second region corresponds to the local transfer control
descriptor memory.
Some registers are implemented as two 32-bit registers, and include H and L suffixes, signaling the high
and low portions of the control function.