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Chapter 5: Standard RLL Instructions - Accumulator/Stack Load and Output Data
Load Accumulator Indexed (LDX)
1
Load Accumulator Indexed is a 16-bit instruction that specifies
230
a source address (V-memory) which will be offset by the value
240
in the first stack location. This instruction interprets the value
2
250-1
in the first stack location as HEX. The value in the offset
address (source address + offset) is loaded into the lower 16
260
3
bits of the accumulator. The upper 16 bits of the accumulator are set to 0.
DS
Used
Helpful hint: — The Load Address instruction can be used to convert an octal address to a
4
HPP Used
HEX address and load the value into the accumulator.
5
V-memory
6
Pointer
7
NOTE: Two consecutive Load instructions will place the value of the first load instruction onto the
accumulator stack.
8
In the following example when X1 is on, the HEX equivalent for octal 25 will be loaded into
the accumulator (this value will be placed on the stack when the Load Accumulator Indexed
9
instruction is executed). V-memory location V1410 will be added to the value in the 1st. level
of the stack and the value in this location (V1435 = 2345) is loaded into the lower 16 bits of
10
the accumulator using the Load Accumulator Indexed instruction. The value in the lower 16
bits of the accumulator is output to V1500 using the Out instruction.
11
12
X1
13
14
A
B
C
D
5–62
DL205 User Manual, 4th Edition, Rev. B
Operand Data Type
LDA
O 25
Load The HEX equivalent to
octal 25 into the lower 16
bits of the accumulator
LDX
V1410
Move the offset to the stack.
Load the accumulator with
the address to be offset
OUT
V1500
Copy the value in the lower
16 bits of the accumulator
to V1500
DL250-1 Range
A
aaa
All. See
V
memory map
All V-memory.
P
See memory map
Octal
Hexadecimal
2
5
0
The unused accumulator
bits are set to zero
Acc. 0
0
0
0
0
HEX Value in 1st
stack location
Octal
1
4
1
0
1
5
1
V
=
V
+
The unused accumulator
bits are set to zero
0
0
0
0
2
Acc.
The value in V1435
is 2345
2
LDX
A aaa
DL260 Range
aaa
All. See
memory map
All V-memory.
See memory map
0
1
5
0
1
5
Accumulator Stack
Octal
4
3
5
0
0
0
0
Level 1
X
X
X
X X
Level 2
Level 3
X
X
X
X X
Level 4
X
X
X
X X
3
4
5
Level 5
X
X
X
X X
X
X
X
X X
Level 6
X
X
X
X X
Level 7
3
4
5
Level 8
X
X
X
X X
V1500
0
0
1
5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
- Quick Links:
- I/O Configuration
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