HOST INTERFACE (HI)
5 - 46
PORT B
MOTOROLA
TRANSFER
HREQ
DMA
0
HF3
HF2
TRD
Y
1
RXDF
2
70
INTERR
UPT ST
ATUS
REGISTER (ISR)
INIT
0
0
HF1
HF0
0
1
RREQ
0
70
VIEW FR
OM HOST
VIEW FR
OM DSP56002
WHEN
TXDE = 1,
TDR IS EMPTY
.
0
0
0
HF1
HF0
HCP
HTDE
0
X:$FFE9
70
HOST ST
A
TUS
REGISTER (HSR)
0
0
0
HF3
HF2
HCIE
HTIE
1
X:$FFE8
70
HOST CONTR
OL
REGISTER (HCR)
TXDE
TRANSMIT D
A
T
A REGISTER EMPTY
INTERR
UPT CONTR
OL
REGISTER (ICR)
HOST MA
Y POLL
TXDE.
TREQ
TRANSMIT REQUEST ENABLE
HM1
HM0
IF
TREQ = 1,
THEN HREQ
PIN IS ASSER
TED
T
O INTERR
UPT HOST
.
HREQ
PIN
HOST
WRITES D
A
T
A
T
O
TRANSMIT BYTE REGISTERS
.
WRITE T
O TXL
CLEARS TXDE
IN
ISR.
6.
IF DSP560022 HAS OLD D
A
T
A IN HRX,
THEN HRDF = 1.
TXH
TXM
TXL
70
$5
$6
LAST WRITE
$7
TRANSMIT BYTE
REGISTERS (TBR)
7.
WHEN DSP56002 READS HRX,
THEN HRDF = 0.
8.
WHEN
TXDE = 0 AND HRDF = 0,
THEN
TRANSFER OCCURS
.
HRDF
HOST RECEIVE D
A
T
A FULL
DMA
HIGH BYTE
MIDDLE BYTE
LO
W BYTE
X:$FFEB
23
0
HOST RECEIVE
D
ATA
REGISTER (HRX)
9.
THE
TRANSFER SETS HRDF FOR
THE DSP56002
T
O POLL.
10.
IF HRDF = 1 AND INTERR
UPTS ARE ENABLED
,
THEN EXCEPTION
PR
OCESSING BEGINS
.
HRIE
HOST RECEIVE INTERR
UPT ENABLE
P:$0020
HOST RECEIVE D
A
T
A
VECT
OR
F
AST INTERR
UPT
OR
LONG INTERR
UPT
Figure 5-24 Data Transfer from Host to DSP
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
.
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