
Instruction Execution Timing
MOTOROLA
M68060 USER’S MANUAL
10-7
The MC68060 superscalar architecture allows pairs of single-cycle standard operations to
be simultaneously dispatched in the operand execution pipelines. Additionally, the design
also permits a single-cycle standard instruction plus a conditional branch (Bcc) predicted
by the branch cache to be dispatched in the OEP. Bcc instructions predicted as not taken
allow another instruction to be executed in the sOEP. This also is true for forward Bcc
instructions that are not predicted.
1 These floating-point instructions are pOEP-but-allows-sOEP except for the following:
F<op>Dm,FPn
F<op>&imm,FPn
F<op>.x<mem>,FPn
which are classified as pOEP-only
Table 10-3. Superscalar Classification of M680x0 Privileged Instructions
Mnemonic
Instruction
Superscalar Classification
ANDI to SR
AND Immediate to Status Register
pOEP-only
CINV
Invalidate Cache Lines
pOEP-only
CPUSH
Push and Invalidate Cache Lines
pOEP-only
EORI to SR
Exclusive OR Immediate to Status Register
pOEP-only
MOVE from SR
Move from Status Register
pOEP-only
MOVE to SR
Move to Status Register
pOEP-only
MOVE USP
Move User Stack Pointer
pOEP-only
MOVEC
Move Control Register
pOEP-only
MOVES
Move Address Space
pOEP-only
ORI to SR
Inclusive OR Immediate to Status Register
pOEP-only
PFLUSH
Flush ATC Entries
pOEP-only
PLPA
Load Physical Address
pOEP-only
RESET
Reset External Devices
pOEP-only
RTE
Return from Exception
pOEP-only
STOP
Load Status Register and Stop
pOEP-only
Table 10-4. Superscalar Classification of M680x0 Floating-Point Instructions
Mnemonic
Instruction
Superscalar Classification
FABS, FDABS, FSABS
Absolute Value
pOEP-but-allows-sOEP1
FADD, FDADD, FSADD
Add
pOEP-but-allows-sOEP1
FBcc
Branch Conditionally
pOEP-only
FCMP
Compare
pOEP-but-allows-sOEP1
FDIV, FDDIV, FSDIV,
FSGLDIV
Divide
pOEP-but-allows-sOEP1
FINT, FINTRZ
Integer Part, Round-to-Zero
pOEP-but-allows-sOEP1
FMOVE, FDMOVE, FSMOVE Move Floating-Point Data Register
pOEP-but-allows-sOEP1
FMOVE
Move System Control Register
pOEP-only
FMOVEM
Move Multiple Data Registers
pOEP-only
FMUL, FDMUL, FSMUL,
FSGLMUL
Multiply
pOEP-but-allows-sOEP1
FNEG, FDNEG, FSNEG
Negate
pOEP-but-allows-sOEP1
FNOP
No Operation
pOEP-only
FSQRT
Square Root
pOEP-but-allows-sOEP1
FSUB, FDSUB, FSSUB
Subtract
pOEP-but-allows-sOEP1
FTST
Test Operand
pOEP-but-allows-sOEP1