7721 datasheet(308/577 Pages) RENESAS

308 / 577 page

7721 Group User’s Manual

13-29

DMA CONTROLLER

13.3 Control

Fig.13.3.4 States of SARi, DARi, TCRi after forced termination

Previously written values

Latch

Transfer source/destination address is specified.

Contents are updated by incrementer/decrementer and

decrementer.

a. State at forced termination

b. When setting DMAi enable bit to “1” without rewriting values at addresses of SARi, DARi, and TCRi

A value read from each latch is used by hardware only at the first 1-unit transfer.

The contents updated by the incrementer/decrementer and the decrementer are loaded in each register.

Values are used by reading them from registers at the second and the following 1-unit transfers.

Latch

Previously written values

Updated contents are written.

c. When reading values at addresses of SARi, DARi, and TCRi after forced termination and rewriting them

Latch

Previously written values

Written by software

Read by software

Addresses which were to be

transferred subsequently or the

number of remaining bytes

Addresses which were to be

transferred subsequently or the

number of remaining bytes

Addresses which were to be

transferred subsequently or the

number of remaining bytes

Addresses which were to be

transferred subsequently or the

number of remaining bytes

7721 Datasheet(PDF) 308 Page - Renesas Technology Corp