mc68ec060 Freescale Semiconductor, Inc, mc68ec060 Datasheet - Page 252

• Manufacturer Part Number: mc68ec060
• Description: Mc68060 Superscalar 68k Microprocessor Including The Lc060 And Ec060
• Manufacturer: Freescale Semiconductor, Inc

Exception Processing
8.4.2 Six-Word Stack Frame (Format $2)
If a six-word stack frame is on the stack and an RTE instruction is encountered, the proces-
sor restores the SR and PC values from the stack, increments the SSP by $C, and resumes
normal instruction execution.
8.4.3 Floating-Point Post-Instruction Stack Frame (Format $3)
In this case, the processor restores the SR and PC values from the stack and increments
the supervisor stack pointer by $C. If another floating-point post-instruction exception is
pending, exception processing begins immediately for the new exception; otherwise, the
processor resumes normal instruction execution.
8-20
SP
SP
+$02
+$06
+$08
+$02
+$06
+$08
15
15
0 0 1 0
0 0 1 1
FLOATING-POINT POST-INSTRUCTION
SIX-WORD STACK FRAME–FORMAT $2
Stack Frames
Stack Frames
STACK FRAME–FORMAT $3
PROGRAM COUNTER
PROGRAM COUNTER
EFFECTIVE ADDRESS
STATUS REGISTER
STATUS REGISTER
ADDRESS
VECTOR OFFSET
VECTOR OFFSET
M68060 USER’S MANUAL
0
0
• CHK, CHK2 (Emulated),
• Unimplemented Floating-
• Address Error
• Floating-Point Post-Instruction • Next Instruction; Effective
TRAPcc, FTRAPcc(Emulat-
ed), TRAPV, Trace, or Zero Di-
vide
Point Instruction
Exception Types
Exception Types
• Next Instruction; Address field
• Next Instruction; Address field
• Instruction that caused the ad-
Address field is the calculated
effective address for the float-
ing-point instruction.
has the address of the instruc-
tion that caused the excep-
tion.
has the calculated <ea> for
the floating-point instruction.
dress error; Address field has
the branch target address with
A0=0.
Effective Address Field
Stacked PC Points To;
Stacked PC Points To;
Address Field Has
MOTOROLA