Motorola DSP56012 ユーザーズマニュアル

Host to DSP DMA Procedure

WRITE ICR

X:$FFE8

HOST CONTR

OL

REGISTER (HCR)

P:$007E

A

V

AILABLE FOR HOST COMMAND

F

AST INTERR

UPT

OR

LONG INTERR

UPT

P:$0000

HOST TRANSMIT 

D

A

T

A

 VECT

OR

P:$0032

PR

OGRAM DMA CONTR

OLLER.

—ST

AR

T ADDRESS

—BYTE COUNT

—TRANSFER DIRECTION

—ST

AR

T DMA CHANNEL

TXH

TXM

TXL

TXH

TXM

TXL

•

•

•

TXH

TXM

TXL

01

10

11

01

10

11

01

10

11

INITIALIZE DSP56012 HOST INTERF

A

CE.

—MODE 24 BIT DMA

—HOST T

O

 DSP

—USE INIT BIT 

T

O

:

SET TXDE

CLEAR HRDF

LO

AD DMA COUNTER

HOST IS FREE 

T

O

 PERFORM 

O

THER 

T

ASKS (i.e

., DSP 

T

O

 HOST 

TRANSFER ON A POLLED BASIS).

TERMINA

TE DMA CHANNEL.

TERMINA

TE DSP DMA MODE BY

 

CLEARING HM1, HM0, AND 

TREQ.

DMA CONTR

OLLER INTERR

UPTS HOST 

WHEN 

TRANSFERS ARE DONE.

HOREQ

PIN

DMA CONTR

OLLER PERFORMS READS

.

$0

INTERR

UPT

CONTR

OL

REGISTER (ICR)

ASSER

T HOREQ

 T

O

 ST

AR

T DMA 

TRANSFER.

interr

upt VECT

OR T

ABLE

TELL DSP56012

—WHERE 

T

O

 ST

ORE D

A

T

A

 (i.e

., PR

OGRAM 

ADDRESS REGISTER R7).

—ENABLE INTERR

UPT HRIE (CAN BE 

DONE 

WITH A HOST COMMAND).

1

HF1

HF0

1

0

70

1

0

6

5

432

1

0

INIT

HM1

HM0

TREQ

RREQ

0

HF3

HF2

HTIE

1

70

0

0

6

5

432

1

HCIE

HRIE

AA0343.11

Note: When using the SAI and DAX 

peripherals, do not use interrupt vector 

addresses P:$0040–$004A, $0050, 

$0052, and $0056.