Binary Subtract -- Sbb - Omron CPM1 Programming Manual

Example
TR 0
00000
25504
25504
7-21-2 BINARY SUBTRACT - - SBB(51)
Limitations
The following example shows a four-digit addition with CY used to place either
#0000 or #0001 into R+1 to ensure that any carry is preserved.
In the case below, A6E2 + 80C5 = 127A7. The result is a 5-digit number, so CY
(SR 25504) = 1, and the content of R + 1 becomes #0001.
Note For signed binary calculations, the status of the UF and OF flags indicate wheth-
er the result has exceeded the signed binary data range (--32,768 (8000) to
+32,767 (7FFF)).
Ladder Symbols
SBB(51)
Mi
Su
R
DM 6144 to DM 6655 cannot be used for R.
Address Instruction
00000
CLC(41)
00001
00002
ADB(50)
00003
200
DM 0100
HR 10
= R
00004
MOV(21)
00005
#0000
HR 11
= R+1
00006
MOV(21)
00007
#0001
00008
HR 11
= R+1
Au: IR 200
A 6
+ Ad: DM 0100
8 0
R+1: HR 11 R: HR 10
0 0 0 1 2 7
IR, SR, AR, DM, HR, TC, LR, #
@SBB(51)
Mi
IR, SR, AR, DM, HR, TC, LR, #
Su
R
Section
Operands
LD 00000
OUT TR
CLC(41)
ADB(50)
DM
HR
AND NOT 25504
MOV(21)
#
HR
LD TR
AND 25504
MOV(21)
# 00001
HR
E 2
C 5
A 7
Operand Data Areas
Mi: Minuend word (binary)
Su: Subtrahend word (binary)
R: Result word
IR, SR, AR, DM, HR, LR
7-21
0
200
0100
10
0000
11
0
11