Symbols And Notation - Motorola HC12 Refrence Manual

1.3 Symbols and Notation

The following symbols and notation are used throughout the manual. More specialized
usages that apply only to the instruction glossary are described at the beginning of that
section.
1.3.1 Abbreviations for System Resources
A — Accumulator A
B — Accumulator B
D — Double accumulator D (A : B)
X — Index register X
Y — Index register Y
SP — Stack pointer
PC — Program counter
CCR — Condition code register
S – STOP instruction control bit
X– Non-maskable interrupt control bit
H – Half-carry status bit
I – Maskable interrupt control bit
N – Negative status bit
Z – Zero status bit
V – Two's complement overflow status bit
C – Carry/Borrow status bit
1.3.2 Memory and Addressing
M — 8-bit memory location pointed to by the effective address of the in-
struction
M : M+1 — 16-bit memory location. Consists of the location pointed to by the
effective address concatenated with the next higher memory loca-
tion. The most significant byte is at location M.
M~M+3 — 32-bit memory location. Consists of the effective address of the
M ~M instruction concatenated with the next three higher memory
(Y) (Y+3)
locations. The most significant byte is at location M or M
M — Memory locations pointed to by index register X
(X)
M — Memory locations pointed to by the stack pointer
(SP)
M Memory locations pointed to by index register Y plus 3,
(Y+3)
—
respectively.
PPAGE — Program overlay page (bank) number for extended memory
(>64K).
Page — Program overlay page
X — High-order byte
H
X — Low-order byte
L
( ) — Content of register or memory location
$ — Hexadecimal value
% — Binary value
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