HOST INTERFACE (HI)
5 - 62
PORT B
MOTOROLA
WRITE ICR
HOST PR
OCESSOR
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:$0022
1.
PR
OGRAM DMA CONTR
OLLER.
—
ST
AR
T ADDRESS
—
BYTE COUNT
—
TRANSFER DIRECTION
—
ST
AR
T DMA CHANNEL
RXH
RXM
RXL
RXH
RXM
RXL
•
•
•
RXH
RXM
RXL
01
10
11
01
10
11
01
10
11
DSP56002
DMA CONTR
OLLER
2.
INITIALIZE DSP56002 HOST INTERF
A
CE.
—
MODE 24 BIT DMA
—
HOST T
O
DSP
—
USE INIT BIT
T
O:
CLEAR TXDE
SET HRDF
LO
AD DMA COUNTER
5.
HOST IS FREE
T
O PERFORM
O
THER
T
ASKS (i.e
., DSP
T
O HOST
TRANSFER ON A POLLED BASIS).
8.
TERMINA
TE DMA CHANNEL.
9.
TERMINA
TE DSP DMA MODE BY
CLEARING HM1, HM0, AND
TREQ.
7.
DMA CONTR
OLLER INTERR
UPTS HOST
WHEN
TRANSFERS ARE DONE.
0
0
0
HF3
HF2
HCIE
1
HTIE
70
HRIE
HREQ
6.
DMA CONTR
OLLER PERFORMS READS
.
1
0
1
HF1
HF0
0
0
1
$0
70
INTERR
UPT
CONTR
OL
REGISTER (ICR)
INIT
HM1
HM0
TREQ
RREQ
4.
ASSER
T HREQ
T
O ST
AR
T DMA
TRANSFER.
EXCEPTION VECT
OR T
ABLE
3.
TELL DSP56002.
—
SOURCE POINTER ADDRESS
—
ENABLE HTIE (CAN BE DONE
WITH A HOST COMMAND).
Figure 5-40 DSP to Host DMA Procedure
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..
Содержание DSP56002
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