HOST INTERFACE (HI)
5 - 54
PORT B
MOTOROLA
VIEW FR
OM HOST
DMA
0
0
HF1
HF0
HCP
1
HRDF
X:$FFE9
70
HOST ST
A
TUS
REGISTER (HSR)
0
0
0
HF3
HF2
HCIE
1
HRIE
X:$FFE8
70
HOST CONTR
OL
REGISTER (HCR)
1.
WHEN HTDE = 1,
THEN HTX IS EMPTY
.
2.
DSP56002 MA
Y POLL HTDE.
7.
THE
TRANSFER SETS RXDF FOR
THE HOST
T
O POLL.
HTDE
HOST
TRANSMIT D
A
T
A EMPTY
HTIE
HOST
TRANSMIT INTERR
UPT ENABLE
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
5.
READ OF RXL BY HOST CLEARS RXDF IN ISR.
6.
WHEN RXDF = 0 AND HTDE = 0,
THEN
TRANSFER OCCURS
.
RXH
RXM
RXL
70
$5
$6
LAST READ
$7
RECEIVE BYTE
REGISTERS (RBR)
HREQ
DMA
0
HF3
HF2
TRD
Y
TXDE
1
$2
70
INTERR
UPT
ST
ATUS
REGISTER (ISR)
RXDF
RECEIVE
D
A
T
A FULL
INIT
HM1
HM0
HF1
HF0
0
TREQ
1
$0
70
INTERR
UPT
CONTR
OL
REGISTER (ICR)
RREQ
RECEIVE
REQ
UEST ENABLE
8.
IF RREQ = 1,
THEN HREQ
PIN IS ASSER
TED
T
O INTERR
UPT HOST
.
HREQ
PIN
VIEW FR
OM HOST
3.
IF HTIE = 1, AND INTERR
UPTS ARE ENABLED
,
THEN EXCEPTION
PR
OCESSING BEGINS
.
4.
DSP56002
WRITES D
A
T
A
T
O HTX,
WHICH CLEARS HTDE IN HSR.
HIGH BYTE
MIDDLE BYTE
LO
W BYTE
X:$FFEB
23
0
HOST RECEIVE
D
ATA
REGISTER (HSR)
Figure 5-33 Data Transfer from DSP to Host
F
re
e
sc
a
le
S
e
m
ic
o
n
d
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to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..