Table 12-10.
CPU to AT-Bus, On-board I/O, and ROM----Formula Specifications
16MHz
20MHz
Symbol
Critical Path
Formula
Min.
Max.
Min.
Max.
te133
ALE width
t133-t134
----
10
----
10
te137
MODA0 hold after command rise
t136-t137
----
16
----
16
te139
MEMCS16 setup before ALE fall
t139-t134
----
24**
----
15**
te145
Master read, access from CAS
t145+t102
----
38*
----
38*
te145a
Master read, access from Column
Address
t145+t107
----
34
----
34
*
** 20ns maximum for 82C836A-20. 29ns maximum for 836A-16.
36ns maximum for 82C836A.
Table 12-11.
CPU to AT-Bus, On-board I/O, and ROM----Input Requirements
16MHz
20MHz
Symbol
Parameters
Min.
Max.
Min.
Max.
t160
-ADS setup before PROCCLK rise*
24
----
24
----
t161
-ADS hold after PROCCLK rise*
A0-23 setup before PROCCLK rise
A0-23 hold after PROCCLK rise
-BHE setup before PROCCLK rise
-BHE hold after PROCCLK rise
-DC, W/-R and M/-IO setup before PROCCLK rise
-DC, W/-R and M/-IO hold after PROCCLK rise
IOCHRDY setup before BUSCLK rise
+
IOCHRDY hold after BUSCLK rise
+
0WS setup before BUSCLK fall
+
0WS hold after BUSCLK fall
+
4
----
4
----
t162
57
----
45
----
t163
4
----
4
----
t164
39
----
39
----
t165
4
----
4
----
t166
39
----
39
----
t167
4
----
4
----
t168
20
----
15
----
t169
20
----
15
----
t170
15
----
10
----
t171
25
----
20
----
t173
-IOCS16 hold after Command inactive
0
----
0
----
t174
-MEMCS16 setup before ALE fall
33**
----
30**
----
t175
-MEMCS16 hold after ALE fall
10
----
10
----
t176
XD0-15 valid before read command rise
25
----
20
----
t177
-IOCS16 setup before BUSCLK rise (first BUSCLK
rise after I/O command fall)
0
----
0
----
+
Certain input parameters, as noted, are nonrestrictive. If these parameters are violated, the sign
until the subsequent clocking period. The parameter specifies only the condition needed to guarante
signal on the particular clock edge.
At end of TS (TS is the T-state in which -ADS changes from low to high).
At mid-TS.
At start of TS.
** 28ns maximum for 82C836A at 16MHz. 25ns maximum for 82C836A at 20MHz.
al may not be recognized
e recognition of the
*
System Characteristics
AC Characteristics 16- and 20MHz
I
Chips and Technologies, Inc.
P R E L I M I N A R Y
Revision 3.0
12-7