Dram Timing - Tandy 26-3334 Service Manual

Read Cycle
RAS
VIH
~
VIL-
\
CAS
VIH-
-X
VI
L-
/
tCRP
A0-A7 VfH-
VI
L-
WE
VIH-^
VI
L-
OE
VIH
~
^
VI
L-
1/01-1/04
VOH-
VOL-
tASR
-tAR-
tRAS
(175ns)
tRC
(280nsf
-^
—
_tRCD-— -
tRAH
[35 ns)
tASC
(35
ns)
^
ROW
ADDRESS
-tCSH-
tCAH
COLUMN
ADDRESS
tRCS
r~^\
-tRSH—
tCAS
(140ns)
-~4
4
—
trow
*
-tOES-
tRP
'(105
ns}"
tCPN
(140ns)
.
tf
HH j
smK
-tCAC-
-tRAC-
Hl-Z
<
tRCH
tOFF
tOEZ
VAUI
DATA
r>
<&
z
Write Cycle
RAS
VIH-
VIL-
CAS
VIH-
VIL-
A0-A7
VIH- 7/7
VIL-
y/
WE VIH-
VI L-
^:
tASR
tRC
-tAR-
tRAS
(280
ns)
'(175
ns)
-tRCD-
tRAH
tASC
^
(35ns)
(35ns
ROW
ADDRESS
tCAH
COLUMN
ADDRESS
1/01-1/04
VIH- '/////,
VIL-
tWCS
-
tWCR
tWP
•tDS
-tCSH
-tRSH-
tCAS
Z
"(140 ns)
tWCH
-tDH-
/ \
.tRP
(105
ns)
£J
'\I
tCPN
_
(140
ns)
2
^/////////////////////////A
VALID
DATA
-tDHR-
:
^^%^%%^^
Fig
5-5,
DRAM Timing
-35-