Intel 80386

LOCAL BUS CONTROL PAL DESCRIPTIONS
" Macros:
COUNTING macro
( (Q1 # QO) ); " true until sequencer counts down to zero
LOWCOUNTING macro
« QO)}; " true until sequencer counts down to zero
" same as COUNTING except used to reduce PAL
" terms and only works if count less than
't"IIIIIII'II""'IIIIII"""'I'I'"IIIIIIIIIIII""I'""""""'IIIII""H""""I'""IIIII,I'I'""""'IIIIIII"IIIIII'111111111"1111"1'
state_diagram BUSSTATE
state IDLEBUS:
if RESET then IDLEBUS
else if ICLK # ADS then
else
"bus is idle or first
"reset to J.DLEBUS
IDLEBUS "remain til sample
ACTlVEBUS; " ••• then go ACTIVE
CLK of unpipelined
ADS active
state ACTIVEBUS:
if RESET then IDLEBUS
"subsequent CLKS of active bus
"reset to IDLEBUS
else if ICLK # READY then ACTlVEBUS
else if lADS then PIPEBUS '
"remain til sample READY active
" ••• then next cycle either piped
else IDLEBUS;
state PIPEBUS:
if RESET then IDLE BUS
else if ICLK then PIPEBUS
else ACTIVEBUS;
state ILLEGALBUS:
goto IDLEBUS;
" ••• or idle
"first CLK of pipelined cycle
"reset to IDLEBUS
"remain for just one CLK
" ••• then go ACTIVE
"unused state - should never occur
"if entered upon power-up •.. go IDLE
11"'1111"111111"1""""'1"""""""""111'"11""""""',",",n"IIIIIIIIIIIIIIII'I"'I'I",,"""'IIIIIII""1111111'1111"1""1111111111111
state_diagram LOCALS TATE
state WAITING: "waiting for next bus cycle
NA := OFF;
if RESET then WAITING "reset to WAITING
else if ICLK
# ( ADS & IDLE} "remain while idle bus
#( ICSIO & LOWCOUNTING) then WAITING " .. and remain for recovery time
else SAMPLECS;" .• else begin bus cycle
state SAMPLECS:
NA := OFF;
if RESET then WAITING
else if ICS1WS then MEMORY
else if !CSIO then CMDDELAY
else NOTLOCAL;
state CMDDELAY:
NA := OFF;
if RESET then WAITING
else 10;
state 10:
NA := (!COUNTING & CLK) # NA;
if RESET then WAITING
else if !NA then 10
else ENDIO;
state ENDIO:
NA := OFF;
if RESET then WAITING
else if LOWCOUNTING then ENDIO
else FLOAT;
"CLK2 before ALE falls and CS is sampled
"reset to WAITING
"start lWS access
"start 10 access
"start non-local access
"delay before CMD active
"reset to WAITING
"only in state for 1 CLK2, then 10
"10 CMD active
"activate NA after count down to zero
"reset to WAITING
"remain until NA active
" ... then ENDIO
"10 CMD active
"reset to WAITING
"remain while COUNTING down
" •.. then FLOAT
Figure A-1. PAL-1 State Listings (Cont'd.)
A-4