Maxim Integrated MAX31782 - Manual (Page 211)

MaximIntegrated 20-28
MAX31782 User’s Guide
Revision 0; 8/11
SUB/SUBBsrc Subtract/SubtractwithBorrow
Description: Subtracts the specified src from the active accumulator (Acc) and returns the result back to the
active accumula- tor . The SUBB additionally subtracts the borrow (Carry Flag), which may have
resulted from previous subtraction . For the complete list of src specifiers, reference the MOVE
instruction . Because the source is limited to 8 bits, the PFX[n] register is used to supply the high-
byte of data for 16 bit sources .
StatusFlags: C, S, Z, OV
SUBOperation: Acc ← Acc - src
Encoding: 15 0
f101 1010 ssss ssss
Example(s): ; Acc = 2345h to start, A[1]= 1250h
SUB A[1] ; Acc = 10F5h, C=0, S=0, Z=0, OV=0
SUB A[1] ; Acc = FEA5h, C=1, S=1, Z=0, OV=0
SUB A[2] ; A[2] =7FFFh
; → Acc = 7EA6h; C=0, S=0, Z=0, OV=1
SUBBOperation: Acc ← Acc - (src + C)
Encoding:
15 0
f111 1010 ssss ssss
Example(s): ; Acc = 2345h, A[1]= 1250h, C=1
SUBB A[1] ; Acc = 10F4h, C=0, S=0, Z=0
SUBB A[1] ; Acc = FEA4h, C=1, S=1, Z=0
SpecialNotes: The active accumulator (Acc) is not allowed as the src for these operations .