Technical data

Further applications for organization blocks OB 190 to 193
- In the CPU 928B, operations involving the processing of single bits
(A, O, ON, AN, S, R, =) that access the flag area are far faster than
comparable operations that access data blocks (compare, for example the
operations "A F"
"A D" or "S F" "S D").
You can speed up your program if you copy data to the flag area,
process them there and then return them to the data block.
- A high byte and low byte in a data block can be swapped over without
complicated programming by copying the data words to the flag area
using the appropriate OBs and then transferring them back as
illustrated by Fig. 6-10.
- You can shift data fields within a data block by specifying a different
data word but the same DB number for transferring the data back to
the DB.
OB 190 OB 193
DW x
DW x
A B
C D
B A
D C
Flags
15 8 7 0
Data block
15 8 7 0
Data block
FY y
FY y+1
FY y+2
.
.
.
.
DW x+1
DW x+1
C
D
B
A
70
Fig. 6-10 Swapping the high byte and low byte in a DB using OB 193/OB 190
OB 191/OB 193: Transferring Data Fields to a Flag Area
CPU 928B Programming Guide
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