intJ80386

5.4.6 Shutdown Indication Cycle

The 80386 shuts down as a result of a protection fault while attempting to process a double fault. Sig- naling its entrance into the shutdown state. a shut- down indication cycle is performed. The shutdown indication cycle is identified by the state of the bus definition signals shown in 5.2.5 Bus Cycle Defini- tion and a byte address of O. BEO# and BE2# are

the only signals distinguishing shutdown indication from halt indication. which drives an address of 2. During the shutdown cycle undefined data is driven on 00-031.The shutdown indication cycle must be acknowledged by READY # asserted.

A shutdown 80386 resumes execution when NMI or RESET is asserted.

CYCLE 1

CYCLE 2

I IDLE

 

 

 

PIPELINED

PIPELINED

 

 

 

(READ)

(SHUTDOWN)

 

 

 

 

T1 P

T2P

T1 P

T21

Ti

Ti

Ti

Ti

ClK2[

 

 

 

 

 

 

 

(82384 ClK) [

 

 

BEl #. BE2#. BE3#. [

~---+.,....-+---r,.~~ir-7'I:~d~~~ 80386 REMAINS SHUTDOWN

M/IO#. W/R#

'Clt/.::.J.~ID.~~t/.::.J.~*- UNTil NMI OR RESET

 

-

IS ASSERTED•

BEO#. A2-A31. [

/'V'I:'?~~~~

I

O/C# ~~~~~-~--~~~~~~~~~80386RESPONOSTO

ADS#[

~-+---l---!---+HOLD INPUT WHilE IN THE SHUTDOWN STATE.

NA#[

READY# [

lOCK#[

00-031 [

231630-28

Figure 5-24. Shutdown Indication Cycle

88

Page 149
Image 149
Intel 80386 manual Shutdown Indication Cycle