9.2
Memory Access via Address in ACCU 1
Application
The operations listed in this section are suitable primarily for access to
data blocks and other operand areas. You should, however, not access
blocks containing STEP 5 programs (OBs, FBs, PBs and SBs) with
these operations.
To access these areas, you can use various 16 or 32-bit wide registers.
These registers include the accumulators ACCU 1 to ACCU 4 and
other special registers used as resources by the CPU.
Operations
Operation
Operand Function
LIR
Register
no.
0 to 15
Load the 16-bit register with the content
of a memory word addressed by ACCU 1
(20-bit address).
TIR
Register
no.
0 to 15
Load the content of the 16-bit register in
the memory word addressed by ACCU 1
(20-bit address).
LDI
Register
name
Load the 32-bit register with the contents
of the memory words ’n’ and ’n+1’
addressed by ACCU 1 (20-bit address).
TDI
Register
name
Load the contents of the 32-bit register in
the memory words ’n’ and ’n+1’ addressed
by ACCU 1 (20-bit address).
The absolute address of the memory word or the first of the two
memory words is located in ACCU 1 in the following representation:
The following pages explain which registers you can use with the
operations.
Examples explain how to use the operations.
Table 9-1
Operations for indirect memory access using registers
Bit no.
ACCU-1-H
ACCU-1-L
31
20 19
16 15
0
Address bits
Address bits 0 to 15
16 to 19
Memory Access via Address in ACCU 1
CPU 948 Programming Guide
9 - 8
C79000-G8576-C848-04
Summary of Contents for CPU 948
Page 10: ...Contents CPU 948 Programming Guide 1 2 C79000 G8576 C848 04 ...
Page 32: ...Contents CPU 948 Programming Guide 2 2 C79000 G8576 C848 04 ...
Page 72: ...Data Blocks CPU 948 Programming Guide 2 42 C79000 G8576 C848 04 ...
Page 74: ...Contents CPU 948 Programming Guide 3 2 C79000 G8576 C848 04 ...
Page 154: ...Contents CPU 948 Programming Guide 4 2 C79000 G8576 C848 04 ...
Page 200: ...Contents CPU 948 Programming Guide 5 2 C79000 G8576 C848 04 ...
Page 308: ...Contents CPU 948 Programming Guide 7 2 C79000 G8576 C848 04 ...
Page 324: ...Examples of Parameter Assignment CPU 948 Programming Guide 7 18 C79000 G8576 C848 04 ...
Page 326: ...Contents CPU 948 Programming Guide 8 2 C79000 G8576 C848 04 ...
Page 370: ...Addressable System Data Area CPU 948 Programming Guide 8 46 C79000 G8576 C848 04 ...
Page 372: ...Contents CPU 948 Programming Guide 9 2 C79000 G8576 C848 04 ...
Page 486: ...Contents CPU 948 Programming Guide 11 2 C79000 G8576 C848 04 ...
Page 522: ...PG Functions via the S5 Bus CPU 948 Programming Guide 11 38 C79000 G8576 C848 04 ...
Page 524: ...Contents CPU 948 Programming Guide 12 2 C79000 G8576 C848 04 ...
Page 538: ...Contents CPU 948 Programming Guide 13 2 C79000 G8576 C848 04 ...
Page 546: ...List of Key Words CPU 948 Programming Guide Index 6 C79000 G8576 C848 04 ...