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MOTOROLA
M68040 USER’S MANUAL
1-13
Table 1-3. Notational Conventions (Concluded)
Register Codes
*
General Case.
C
Carry Bit in CCR
cc
Condition Codes from CCR
FC
Function Code
N
Negative Bit in CCR
U
Undefined, Reserved for Motorola Use.
V
Overflow Bit in CCR
X
Extend Bit in CCR
Z
Zero Bit in CCR
—
Not Affected or Applicable.
Stack Pointers
ISP
Supervisor/Interrupt Stack Pointer
MSP
Supervisor/Master Stack Pointer
SP
Active Stack Pointer
SSP
Supervisor (Master or Interrupt) Stack Pointer
USP
User Stack Pointer
Miscellaneous
<ea>
Effective Address
<label>
Assemble Program Label
<list>
List of registers, for example D3–D0.
LB
Lower Bound
m
Bit m of an Operand
m–n
Bits m through n of Operand
UB
Upper Bound
1.10 INSTRUCTION SET OVERVIEW
The instruction set is tailored to support high-level languages and is optimized for those
instructions most commonly executed. The floating-point instructions for the M68040 are a
commonly used subset of the MC68881/MC68882 instruction set with new arithmetic
instructions to explicitly select single- or double-precision rounding. The remaining
unimplemented instructions are less frequently used and are efficiently emulated in the
M68040FPSP, maintaining compatibility with the MC68881/MC68882 floating-point
coprocessors. The M68040 instruction set includes MOVE16, a new user instruction that
allows high-speed transfers of 16-byte blocks between external devices such as memory
to memory or coprocessor to memory. Table 1-4 provides an alphabetized listing of the
M68040 instruction set’s opcode, operation, and syntax. Refer to Table 1-3 for notations
used in Table 1-4. The left operand in the syntax is always the source operand, and the
right operand is the destination operand. Refer to M68000PM/AD, M68000 Family
Programmer’s Reference Manual,for details on instructions used by the M68040.