User manual

8-2
8.1 DMA Introduction
The direct memory access (DMA) controller transfers data from one address
to another, without CPU intervention, across the entire address range. For
example, the DMA controller can move data from the ADC12 conversion
memory to RAM.
MSP430FG43x devices implement only one DMA channel. Therefore some
features described in this chapter are not applicable to MSP430FG43x
devices.
Using the DMA controller can increase the throughput of peripheral modules.
It can also reduce system power consumption by allowing the CPU to remain
in a low-power mode without having to awaken to move data to or from a
peripheral.
The DMA controller features include:
- Up to three independent transfer channels
- Configurable DMA channel priorities
- Requires only two MCLK clock cycles
- Byte or word and mixed byte/word transfer capability
- Block sizes up to 65535 bytes or words
- Configurable transfer trigger selections
- Selectable edge or level-triggered transfer
- Four addressing modes
- Single, block, or burst-block transfer modes
The DMA controller block diagram is shown in Figure 8−1.