User manual

ADD Add to Accumulator
7-24
Execution Increment PC, then ...
Event Addressing mode
(ACC) + ((data-memory address) 2
shift
) → ACC Direct or indirect
(ACC) + ((data-memory address) 2
16
) → ACC Direct or indirect
(shift of 16)
(ACC) + k → ACC Short immediate
(ACC) + lk 2
shift
→ ACC Long immediate
Status Bits Affected by Affects Addressing mode
SXM and OVM C and OV Direct or indirect
OVM C and OV Short immediate
SXM and OVM C and OV Long immediate
Description The content of the addressed data memory location or an immediate constant
is left-shifted and added to the accumulator. During shifting, low-order bits are
zero filled. High-order bits are sign extended if SXM = 1 and zero filled if
SXM = 0. The result is stored in the accumulator. When short immediate ad-
dressing is used, the addition is unaffected by SXM and is not repeatable.
If you are using indirect addressing and update the ARP, you must specify a
shift operand. However, if you do not want a shift to occur, enter a 0 for this
operand. For example:
ADD *+,0,AR2
Normally, the carry bit is set (C = 1) if the result of the addition generates a carry
and is cleared (C = 0) if it does not generate a carry. However, when adding
with a shift of 16, the carry bit is set if a carry is generated but otherwise, the
carry bit is unaffected. This allows the accumulator to generate the proper
single carry when adding a 32-bit number to the accumulator.
Words
Words Addressing mode
1 Direct, indirect, or
short immediate
2 Long immediate