Outline; Single Transfer; Figure 2-2: Single Transfer - Fujitsu FR Series Application Note

2.2 Outline

The DMAC is used to transfer data from one address (space) to another without involving
the CPU. The address space includes RAM, ROM, resource (except DMAC) registers or
external area.

2.2.1 Single Transfer

The following diagram shows a standard interrupt sequence and a single transfer DMA
sequence:
Standard Interrupt Sequence
CPU Task
Application
Peripheral Interrupt
Service Routine
Application
For a single transfer the DMA does not offer a real advantage against a standard interrupt.
MCU-AN-300059-E-V11
DIRECT MEMORY ACCESS
Chapter 2 Direct Memory Access
Interrupt occurs

Figure 2-2: Single Transfer

DMA Sequence
CPU Task
Application
Application
End of DMA interrupts Application
Application
- 8 - © Fujitsu Microelectronics Europe GmbH
DMA Task
Interrupt occurs
DMA Transfer
DMAC Interrupt
Service Routine