Introduction; Key Features - Fujitsu FR Series Application Note

1 Introduction

This application note describes the functionality of the Direct Memory Access Controller
(DMAC) and gives some examples.
The DMAC is mainly used to transfer data between a source and a destination memory
location without any CPU load. The direction can be from resource (peripheral) to memory
and vice versa. This transfer can be a single transfer or multiple transfers from single
address or an address area. DMA is always triggered by a resource interrupt and does not
interrupt the CPU until the transfer has ended.

1.1 Key Features

•
Byte / Half-word / Word Transfer
•
Transfer from External Area / Built-in I/O / Internal RAM to External Area / Built-in I/O
/ Internal RAM
•
Entire space of 32-bit is addressable
•
Step / Block / Bulk / Demand Transfers with possibility of update (increment or
decrement) of source and destination address with Reload
•
Block Count and Transfer Count (with reload) registers available
•
External input pin or built-in peripherals or software requests as DMAC transfer
request sources
•
External Transfer requests available on DMAC channels 0 to 3
•
DMA can be stopped by STOP request (supported by UART-Receive interrupt, in
case of receive error)
MCU-AN-300059-E-V11
DIRECT MEMORY ACCESS
Chapter 1 Introduction
- 6 - © Fujitsu Microelectronics Europe GmbH