Motorola DSP96002 User Manual page 592

B.1.40.1 32 Bit Block Transfer
32 Bit Block Transfer
org
source ds
dest ds
offset ds
count ds
org p:$50
move
move
sub d0,d1
move
move
move
lsl d1,d4
move
do n0,bitblt
lsr d1,d4
lsl d0,d5
or d4,d5
move
bitblt
lsr d1,d4
lsr d0,d5
lsl d0,d5
or d4,d5
move
Where N represents 32 bits transferred. At a 13.5 MIPS, a total of (13.5/4) * 32 = 108 MBits/Second transfer
rate is possible.
MOTOROLA
BITBLT
x:0
1 ;source address
1 ;destination address
1 ;bit number start (0-31)
1 ;number of 32 bit source words
x:offset,d0.l ;get output bit position
#32,d1.l
x:source,r0
x:dest,r1
d1.l,d1.h
y:(r1),d4.l
d0.l,d0.h
x:count,n0
y:(r0)+,d5.l
d5.l,d3.l
d3.l,d4.l
d5.l,y:(r1)+
y:(r1),d5.l
d5.l,y:(r1)
DSP96002 USER'S MANUAL
;get 32
;32-offset, point to source
;point to destination address
;move shift factor
;get first bits of dest
;shift bits, move shift fact
;get source word count
;do transfer
;shift old bits, get source bits 1
;shift new bits, save new bits
;merge bits, save new as old bit 1
;save new dest field
;shift old bits, get dest bits
;shift dest bits
;shift dest bits back
;part of dest with source bits
;save new destination bits
Program ICycles
Words
2 2
1 1
2 2
2 2
1 1
1 1
1 1
2 2
2 3
1
1 1
1
1 1
1 1
1 1
1 1
1 1
1 1
--- ---
Totals: 24 4N+20
B-73