MC68040FE33A Freescale Semiconductor, MC68040FE33A Datasheet - Page 232

• Manufacturer Part Number: MC68040FE33A
• Description: IC MICROPROCESSOR 32BIT 184-CQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68040FE33A

• Processor Type: M680x0 32-Bit
• Speed: 33MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 184-CQFP
• Package: 184CQFP
• Processor Series: M680xx
• Core: CPU32
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: Details

any internal registers, but it does cause the M68040 to assert the reset out (RSTO) signal,
resetting all external devices.
8.3 EXCEPTION PRIORITIES
When several exceptions occur simultaneously, they are processed according to a fixed
priority. Table 8-4 lists the exceptions, grouped by characteristics. Each group has a
priority, from 0–7, with 0 as the highest priority.
* Refer to Section 9 Floating-Point Unit (MC68040 Only) for details concerning floating-point instructions.
The method used to process exceptions in the M68040 is significantly different from that
used in earlier members of the M68000 processor family due to the restart exception
model. In general, when multiple exceptions are pending, the exception with the highest
priority is processed first, and the remaining exceptions are regenerated when the current
instruction restarts. Note that the reset operation clears all other exceptions except in the
following circumstances:
MOTOROLA
Priority
Group/
• As soon as the M68040 has completed exception processing for a condition when an
0
1
2
3
4
5
6
7
8
interrupt exception is pending, it begins exception processing for the interrupt
Reset
Data Access Error
(ATC Fault or Bus Error)
Floating-Point Pre-Instruction*
BKPT #n, CHK, CHK2, Divide by Zero,
FTRAPcc, RTE, TRAP#n, TRAPV
Illegal Instruction, Unimplemented A- and
F-Line, Privilege Violation
Unimplemented Floating-Point Instruction*
Floating-Point Post-Instruction*
Address Error
Trace
Instruction Access Error
(ATC Fault or Bus Error)
Interrupt
Exception and Relative Priority
Freescale Semiconductor, Inc.
Table 8-4. Exception Priority Groups
For More Information On This Product,
Go to: www.freescale.com
M68040 USER’S MANUAL
Aborts all processing (instruction or exception) and does not
save old context.
Aborts current instructions; can have pending trace, floating-
point post-instruction, or unimplemented floating-point
instruction exceptions.
Exception processing begins before current floating-point
instruction is executed. Instruction is restarted on return from
exception.
Exception processing is part of instruction execution.
Exception processing begins before instruction is executed.
Exception processing begins after memory operands are
fetched and before instruction is executed.
Only reported for FMOVE to memory. Exception processing
begins when FMOVE instruction and previous exception
processing have completed.
exceptions have completed.
Exception processing begins when current instruction or
previous exception processing has completed.
Reported after all previous instructions and associated
exceptions have completed.
previous exception processing has completed.
Reported after all previous instructions and associated
Exception processing begins when current instruction or
Characteristics
8- 19