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For brevity, thenotationI(l-7)willbeused for the 7 low-order bits of the instruction word. B (18)
stands for the high-order bit of B. M stands for all 18 bits of the memory location;
B
stands for
all 18 bits of the B Register; C stands for all 7 bits of the C Register. In mnemonic for an
instruction, the first letter has a functional meaning as indicated in the name of each instruction.
At times the discussion will refer to M as a memory location (the effective address, i.e., the
memory location specified by M and the addressing mode). The word times assume that direct
addressing is used; one additional word time is needed for indirect addressing. All instructions
that are directly addressable are also indirectly addressable.
MNEMONIC
OPERAND
LOAD INSTRUCTIONS
LDA
M
LDB
M
LDC
M
LDD
M
LDQ
M
LDZ
M
CMA
M
CMB
M
PIC
I
STORE INSTRUCTIONS
STA
M
STB
M
STC
M
WORD TIMES
2
2
2
3
2
2
2
2
1
2
2
2
DESCRIPTION
LOAD A. The contents of M replace the con-
tents of A. The contents of M are unchanged.
LOAD B. The contents of M replace the con-
tents of B. The contents of M are unchanged.
LOAD C.
The contents of M (1-7) replace
the contents of C. The high order bits of M
are ignored and M is unchanged.
LOAD DOUBLE.
The contents of M replace
the contents A and the contents of M+ 1
replace the contents of B. M must be even.
M and M+ 1 are unchanged.
LOAD
Q.
The contents of M replace the con-
tents of
Q.
The contents of M are unchanged.
LOAD Z. The contents of Mis placed only in
Z and the Branch Flip-Flops.
M remains
unchanged.
COMPLEMENT MEMORY TO
A.
The ones
complement of the contents of M replace the
contents of A.
The contents of M are
unchanged.
COMPLEMENT MEMORY TO B.
The ones
complement of the contents of M replace the
contents of B.
The contents of M remain
unchanged.
PLACE I IN C.
I (1-7) are placed in C.
STORE A. The contents of A replace the con-
tents of M.
The contents of A remain
unchanged.
STORE B. The contents of B replace the con-
tents of M.
The contents
of B remain
unchanged.
STORE C. The
contents of C are
stored
in M (1-7). The contents of M (8-18)
are
reset to Zero and C
remains
unchanged.
[ID£1J£~~1YCJ ~®------------
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