Technical data

Result
•• If the block does exist in the CPU:
-
ACCU-1-L: contains the address of the first data
word (DW 0),
-
ACCU-2-L: contains the length of the data block in words
(without block header),
Example: ACCU-2-L contains the value "7":
the data block consists of DW 0 to DW 6.
-
RLO: = 0
-
CC 0/CC 1: are affected according to the location of the
block (see following list),
-
the remaining
bit and word
condition codes:
are cleared.
•• If the data block does not exist in the memory or the parameter
assignment is incorrect:
-
ACCU 1 and 2: are not changed
-
RLO: = 1
-
CC 0/CC 1: = 1
-
the remaining
bit and word
condition codes:
are cleared
RLO, CC1, CC0 The following condition code bits are set according to the check
result. The condition code bits can be evaluated by the operations
listed in the "Scan" column of the table:
RLO CC 1 CC 0 Scan Meaning
001 JMDB/DX
in user
submodule
DB/DX in
EPROM
(read-only)
DB/DX
exists
0 0 0 JZ DB/DX in RAM
(read/write)
0 1 0 JP DB/DX in DB
RAM
1 1 1 JC DB/DX does not exist or there is an error
6
OB 181: Testing Data Blocks (DB/DX)
CPU 928B Programming Guide
C79000-B8576-C898-01
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