82C836 Datasheet, PDF (188/205 Pages) List of Unclassifed Manufacturers – Single-Chip 386sx AT

s AC Characteristics 25MHz
System Characteristics
Refresh
The refresh timing specifications are shown in Tables 12-40 through 12-42
Table 12-40. Refresh----Output Responses
Symbol
t260
t261
t262
t263
t264
t265
t266
t267
t268
t269
t270
t271
t272
t273
Parameters
-REFRESH active from HLDA
-REFRESH float from OSC2 rise
Refresh address valid from -REFRESH active.
Note: Refresh address refers to MODA0, A0-9 and MA0-9
-XMEMR active from OSC2 rise
-XMEMR inactive from OSC2 rise
-RAS0, -RAS3 active from -XMEMR fall
-RAS0, -RAS3 inactive from -XMEMR rise
-RAS1, -RAS2 active from -XMEMR fall
-RAS1, -RAS2 inactive from -XMEMR rise
LOMEGCS delay from -REFRESH
-CAS fall from HLDA rise in CAS-RAS HLDA refesh
-REFRESH active from PROCCLK in Hidden Refresh, or in HLDA
refresh in Early READY mode following memory write
-XMEMR fall from PROCCLK in Hidden Refresh
-XMEMR rise from PROCCLK in Hidden Refresh
* 40ns maximum for 82C836A.
** Not applicable to 82C836B. 10ns minimum for 82C836A.
Min.
Max.
----
71
----
55
----
45*
----
55
----
50
----
30
----
25
----
70
----
70
----
40
**
----
----
50
----
50
----
50
Table 12-41. Refresh----Formula Specifications
Symbol
te260
te261
te270
te271
te271a
te272
te273
Critical Path
REF to XMEMR delay in HLDA refresh
REF float after XMEMR rise
CAS precharge in CAS-RAS refresh
REF to XMEMR in early READY mode
REF to XMEMR delay in hidden refresh
XMEMR low time in hidden refresh
Address hold after XMEMR rise
* Not applicable for 82C836B. 9ns minimum for 82C836A.
** 1ns maximum for 82C836A.
*** 4ns maximum for 836A.
Formula
t260-t263
t261-t264
t270-t103
t271-t263
t271-t272
t272-t273
t273-t271
Min.
Max.
----
16
----
49
*
----
----
16
----
5**
----
15***
----
23
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