DL205 User Manual, 4th Edition, Rev. B
5–110
Chapter 5: Standard RLL Instructions - Math
1
2
3
4
5
6
7
8
9
10
11
12
13
14
A
B
C
D
Subtract Formatted (SUBF)
Subtract Formatted is a 32-bit instruction that subtracts the
BCD value (Aaaa), which is a range of discrete bits, from the
BCD value in the accumulator. The specified range (Kbbb)
can be 1 to 32 consecutive bits. The result resides in the
accumulator.
NOTE:
Status flags are valid only until another instruction uses the same flag.
In the following example, when X6 is on, the value formed by discrete locations X0–X3 is
loaded into the accumulator using the Load Formatted instruction. The value formed by
discrete location C0–C3 is subtracted from the value in the accumulator using the Subtract
Formatted instruction. The value in the lower four bits of the accumulator is copied to
Y10–Y13 using the Out Formatted instruction.
ý
ý
ý
þ
230
240
2
5
0
-1
2
6
0
SUBF
A aaa
K bbb
Discrete Bit Flags
Description
SP63
On when the result of the instruction causes the value in the accumulator to be zero.
SP64
On when the 16-bit subtraction instruction results in a borrow.
SP65
On when the 32-bit subtraction instruction results in a borrow.
SP70
On anytime the value in the accumulator is negative.
SP75
On when a BCD instruction is executed and a NON-BCD number was encountered.
LDF
X0
K4
X6
SUBF
C0
K4
OUTF
Y10
K4
Copy the lower 4 bits of the
accumulator to discrete
locations Y10--Y13
0 1
0 0 0 0
0
_
0 0 0
0
0
0 0 0 9
(C0--C3)
(Accumulator)
8
X0
X1
X2
X3
ON
OFF
OFF
ON
C0
C1
C2
C3
OFF
OFF
OFF
ON
Y10
Y11
Y12
Y13
ON
OFF
OFF
OFF
The unused accumulator
bits are set to zero
ACC.
Handheld Programmer Keystrokes
STR
$
SHFT
ISG
U
1
B
OUT
GX
SHFT
5
F
0
A
4
E
ENT
6
G
ENT
1
B
4
E
0
A
ENT
SHFT
ANDST
L
3
D
0
A
4
E
ENT
5
F
5
F
RST
S
NEXT
NEXT
NEXT
NEXT
SHFT
Load the BCD value represented
by discrete locations X0-X3 into
the accumulator
Subtract the BCD value
represented by C0-C3 from
the value in the accumulator
Direct
SOFT
Operand Data Type
DL260 Range
A
aaa
bbb
Inputs X
0-1777
-
Outputs Y
0-1777
-
Control Relays C
0-3777
-
Stage Bits S
0-1777
-
Timer Bits T
0-377
-
Counter Bits CT
0-377
-
Special Relays SP
0-777
-
Global I/O GX/GY
0-3777
-
Constant K
-
1-32
DS
Used
HPP Used