Intel 80386 - Page 277

DRAM PAL DESCRIPTIONS
PAL16R8 PAL DESIGN SPECIFICATIONS
PART NUMBER: 3-ClK DRAM CONTROL PAL
DRAM CONTROL PAL OF INTERLEAVED DRAM CONTROllER FOR 80386 SYSTEMS
INTEL, SANTA CLARA, CALIFORNIA
ClK2 ClK BEO BEl BE2 BE3 W%R ROWSEl DISABLE GND
OE CASO CASI DT%R DEN ROY WC CAS2 CAS3 VCC
;drop CAS on read
;drop
on write
/CASO :~ /ROWSEl * ClK * /DT%R * /DISABlE
+ /ROWSEl * WC * ROY * /ClK * /BEO
+ /ROWSEl * /CASO
;ma i nta i n throughout eyel e
;BEx can disappear after CAS drop
;DISABlE must be maintained through last /ROWSEl * ClK
/CASI := /ROWSEl * ClK * /DT%R * /DISA8lE
+ /ROWSEl * WC * ROY * /ClK * /8EI
+ /ROWSEl * /CASI
/CAS2 : = /ROWSEl * ClK * /DT%R * /DISA8lE
+ /ROWSEl * WC * ROY * /ClK * /BE2
+ /ROWSEl * /CAS2
/CAS3 := /ROWSEl * ClK * /DT%R * /DISABlE
+ /ROWSEl * WC * ROY * /ClK * /8E3
+ /ROWSEl * /CAS3
;drop CAS on read
;drop
on write
;maintain throughout cycle
; drop CAS on read
;drop
on write
;maintain throughout cycle
;drop
CAS on read
;drop
on write
;maintain throughout cycle
/DT%R : = ROWSEl * DEN * /W%R
+ /ROWSEl * /DT%R
; samp 1 e W%R when /ROWSEl * DEN
;otherwise: maintain state
+ /DEN * /DT%R
/DEN:= ClK * /ROWSEl * /DISA8lE
+ /ClK * /DEN
/WC : = DISABLE
+ ROWSEl
+ /RDY
+ /WC * /ClK
/RDY ,- WC * ClK
+ /RDY * /DEN
;when ClK: sampl e ROWSEl
;otherwi se: rna i nta instate
; keep low if DISA8lE
or /ROWSEl
or /RDY
or already low * /ClK
;drop ROY
;maintain ROY
Figure C-4. 3-ClK DRAM Control PAL Equations
C-15