Chapter 4
Smart Direct Memory Access (SDMA) API
4.1 Overview
The Smart Direct Memory Access (SDMA) API driver controls the SDMA hardware.
It provides an API to other drivers for transferring data between MCU memory space and
the peripherals. It supports the following features:
• Loading channel scripts from the MCU memory space into SDMA internal RAM
• Loading context parameters of the scripts
• Loading buffer descriptor parameters of the scripts
• Controlling execution of the scripts
• Callback mechanism at the end of script execution
4.1.1 Hardware Operation
The SDMA controller is responsible for transferring data between the MCU memory
space and peripherals. It has the following features:
• Multi-channel DMA, supporting up to 32 time-division multiplexed DMA channels.
• Powered by a 16-bit Instruction-Set micro-RISC engine.
• Each channel executes specific script.
• Very fast context-switching with two-level priority based preemptive multi-tasking.
• 4-KB ROM containing startup scripts (that is, boot code) and other common utilities
that can be referenced by RAM-located scripts.
• 8-KB RAM area is divided into a processor context area and a code space area used
to store channel scripts that are downloaded from the system memory.
i.MX 6Solo/6DualLite Linux Reference Manual, Rev. L3.0.35_4.1.0, 09/2013
Freescale Semiconductor, Inc.
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