Fujitsu MB91460 SERIES Nota de aplicação - Página 6

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Também para Fujitsu MB91460 SERIES: Manual do utilizador (45 páginas), Começar a trabalhar (41 páginas), Nota de aplicação (23 páginas), Nota de aplicação (26 páginas), Nota de aplicação (29 páginas)

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.

•

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

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