SUBB3
Subtract Integer With Borrow, 3-Operand
13-224
Syntax
SUBB3
src2, src1, dst
Operation
src1 – src2 – C
→
dst
Operands
src1 3-operand addressing modes (T):
0 0
register (R
n1, 0
≤
n1
≤
27)
0 1
indirect (
disp = 0, 1, IR0, IR1)
1 0
register (R
n1, 0
≤
n1
≤
27)
1 1
indirect (
disp = 0, 1, IR0, IR1)
src2 3-operand addressing modes (T):
0 0
register (R
n2, 0
≤
n2
≤
27)
0 1
register (R
n2, 0
≤
n2
≤
27)
1 0
indirect (
disp = 0, 1, IR0, IR1)
1 1
indirect (
disp = 0, 1, IR0, IR1)
dst register (Rn, 0
≤
n
≤
27)
Opcode
31
24 23
16
8 7
0
15
0 0 1
0 0
0
1
0
1
dst
T
src1
src2
Description
The difference among the
src1 and src2 operands and the C flag is loaded into
the
dst register. The src1, src2, and dst operands are assumed to be signed
integers.
Cycles
1
Status Bits
These condition flags are modified only if the destination register is R7 – R0.
LUF
Unaffected
LV
1 if an integer overflow occurs; unchanged otherwise
UF
0
N
1 if a negative result is generated; 0 otherwise
Z
1 if a 0 result is generated; 0 otherwise
V
1 if an integer overflow occurs; 0 otherwise
C
1 if a borrow occurs; 0 otherwise
OVM
Operation is affected by OVM bit value.
Mode Bit