HOST INTERFACE (HI)
MOTOROLA
PORT B
5 - 59
WRITE ICR
HOST PR
OCESSOR
1
0
1
HF1
HF0
0
1
0
$0
70
INTERR
UPT
CONTR
OL
REGISTER (ICR)
X:$FFE8
HOST CONTR
OL
REGISTER (HCR)
4.
ASSER
T HREQ
T
O ST
AR
T DMA
TRANSFER.
P:$007E
A
V
AILABLE FOR HOST COMMAND
F
AST INTERR
UPT
OR
LONG INTERR
UPT
P:$0000
HOST RECEIVE D
A
T
A
VECT
OR
P:$0020
1.
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
DSP56002
DMA CONTR
OLLER
2.
INITIALIZE DSP56002 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
3.
TELL DSP56002
—
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).
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.
6.
DMA CONTR
OLLER PERFORMS
WRITES
.
7.
DMA CONTR
OLLER INTERR
UPTS HOST
WHEN
TRANSFERS ARE DONE.
INIT
HM1
HM0
TREQ
RREQ
0
0
0
HF3
HF2
HCIE
HTIE
1
70
HRIE
HREQ
PIN
EXCEPTION VECT
OR T
ABLE
Figure 5-39 Host-to-DSP 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
.
..