MOTOROLA

More For
Information
.wwwGoto:	PORT
freescale	B
On
This
com.
Product,

59 - 5

Freescale Semiconductor, Inc.

HOST PROCESSOR

DMA CONTROLLER

DSP56002

1. PROGRAM DMA CONTROLLER.

— START ADDRESS

— BYTE COUNT

— TRANSFER DIRECTION

— START DMA CHANNEL

7

0

WRITE ICR

1

0

1

HF1

HF0

0

1

0

2. INITIALIZE DSP56002 HOST INTERFACE.

$0

— MODE 24 BIT DMA

INIT

HM1

HM0

TREQ

RREQ

— HOST TO DSP

— USE INIT BIT TO:

SET TXDE

CLEAR HRDF

LOAD DMA COUNTER

7

0

3. TELL DSP56002

0

0

0

HF3

HF2

HCIE

HTIE

1

X:$FFE8

— WHERE TO STORE DATA (i.e., PROGRAM

HRIE

ADDRESS REGISTER R7).

—ENABLE INTERRUPT HRIE (CAN BE DONE WITH A HOST COMMAND).

4. ASSERT HREQ TO START DMA TRANSFER.

5. HOST IS FREE TO PERFORM

OTHER TASKS (i.e., DSP TO HOST

6. DMA CONTROLLER PERFORMS WRITES.

HREQ

TRANSFER ON A POLLED BASIS).

PIN

01

TXH

10

TXM

8. TERMINATE DMA CHANNEL.

11

TXL

P:$0000

EXCEPTION VECTOR TABLE

9. TERMINATE DSP DMA MODE BY

01

TXH

CLEARING HM1, HM0, AND TREQ.

10

TXM

P:$0020

HOST RECEIVE DATA VECTOR

11

TXL

•

P:$007E

AVAILABLE FOR HOST COMMAND

•

•

01

FAST INTERRUPT

TXH

OR

10

LONG INTERRUPT

TXM

11

TXL

7. DMA CONTROLLER INTERRUPTS HOST

WHEN TRANSFERS ARE DONE.

Figure 5-39 Host-to-DSP DMA Procedure

INTERRUPT

CONTROL REGISTER (ICR)

HOST CONTROL REGISTER (HCR)

(HI) INTERFACE HOST	Semiconductor, Freescale
	.Inc