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
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
pOEP-only
ANDI to SR
CINV
CPUSH
EORI to SR
MOVE from SR
MOVE to SR
MOVE USP
MOVEC
MOVES
ORI to SR
PFLUSH
PLPA
RESET
RTE
STOP
AND Immediate to Status Register
Invalidate Cache Lines
Push and Invalidate Cache Lines
Exclusive OR Immediate to Status Register
Move from Status Register
Move to Status Register
Move User Stack Pointer
Move Control Register
Move Address Space
Inclusive OR Immediate to Status Register
Flush ATC Entries
Load Physical Address
Reset External Devices
Return from Exception
Load Status Register and Stop
Table 10-4. Superscalar Classification of M680x0 Floating-Point Instructions
Mnemonic
Instruction
Superscalar Classification
FABS, FDABS, FSABS
Absolute Value
pOEP-but-allows-sOEP
1
FADD, FDADD, FSADD
FBcc
FCMP
FDIV, FDDIV, FSDIV,
FSGLDIV
FINT, FINTRZ
Add
Branch Conditionally
Compare
pOEP-but-allows-sOEP
pOEP-only
1
pOEP-but-allows-sOEP
1
Divide
pOEP-but-allows-sOEP
1
Integer Part, Round-to-Zero
pOEP-but-allows-sOEP
1
FMOVE, FDMOVE, FSMOVE Move Floating-Point Data Register
FMOVE
Move System Control Register
FMOVEM
Move Multiple Data Registers
FMUL, FDMUL, FSMUL,
FSGLMUL
FNEG, FDNEG, FSNEG
Negate
FNOP
No Operation
FSQRT
Square Root
pOEP-but-allows-sOEP
pOEP-only
pOEP-only
1
Multiply
pOEP-but-allows-sOEP
1
pOEP-but-allows-sOEP
pOEP-only
1
pOEP-but-allows-sOEP
1
FSUB, FDSUB, FSSUB
Subtract
pOEP-but-allows-sOEP
1
FTST
Test Operand
pOEP-but-allows-sOEP
1