Types of Data Transfers

Based on the memory access capabilities of the DMA (see Table 1), the following sections discuss the different types of data movement between the source and destination memory regions.

• N:1

  This type of transfer is common when sending predefined data packets (such as strings) through a single interface point (such as communications modules transmit registers).

• N:N

  This type of transfer is useful for moving information out of the program Flash or Data EEPROM to SRAM for manipulation by the CPU or other peripherals.

• 1:1

  This type of transfer is common when bridging two different modules data streams together (communications bridge).

• 1:N

  This type of transfer is useful for moving information from a single data source into a memory buffer (communications receive registers).