HARDWARE IMPLEMENTATION

WAIT instruction, which suspends the 80386 exception handler by raising exception 7. The

until BUSY goes inactive. The coprocessor PEREQ pin is used to implement the 80386-

asserts ERROR when it encounters an exception coprocessor protocol. that should be handled by operating system

software; the 80386 in turn invokes the numeric

CLK2 [

BEO, BEl [

ADDRESS AND [

DEFINITION

ADS [

BS16 [

READY [

00-015 [

016-031 [

32-BIT

BUS SIZE

00-015

~-

9IGNORED-

Figure 5-7. Mixed 16- and 32-bit Accesses

5-8

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Image 59
Intel 80386 manual Mixed 16- and 32-bit Accesses