MC68030 Datasheet, PDF (421/602 Pages) Motorola, Inc – ENHANCED 32-BIT MICROPROCESSOR

Coprocessor Interface Description
10.5 EXCEPTIONS
Various exception conditions related to the execution of coprocessor instructions may occur.
Whether an exception is detected by the main processor or by the coprocessor, the main
processor coordinates and performs exception processing. Servicing these coprocessor-
related exceptions is an extension of the protocol used to service standard M68000 Family
exceptions. That is, when either the main processor detects an exception or is signaled by
the coprocessor that an exception condition has occurred, the main processor proceeds
with exception processing as described in 8.1 Exception Processing Sequence.
10.5.1 Coprocessor-Detected Exceptions
Exceptions that the coprocessor detects, also those that the main processor detects, are
usually classified as coprocessor-detected exceptions. These exceptions can occur during
M68000 coprocessor interface operations, internal operations, or other system-related
operations of the coprocessor.
Most coprocessor-detected exceptions are signaled to the main processor through the use
of one of the three take exception primitives defined for the M68000 coprocessor interface.
The main processor responds to these primitives as previously described. However, not all
coprocessor-detected exceptions are signaled by response primitives. Coprocessor-
detected format errors during the cpSAVE or cpRESTORE instruction are signaled to the
main processor using the invalid format word described in 10.2.3.2.3 Invalid Format Word.
MOTOROLA
MC68030 USER’S MANUAL
10-61