
ADuC845/ADuC847/ADuC848
Table 66.
EXTERNAL DATA MEMORY WRITE CYCLE Parameter
t
WLWH
WR Pulse Width
t
AVLL
Address Valid after ALE Low
t
LLAX
Address Hold after ALE Low
t
LLWL
ALE Low to RD or WR Low
t
AVWL
Address Valid to RD or WR Low
t
QVWX
Data Valid to WR Transition
t
QVWH
Data Setup before WR
t
WHQX
Data and Address Hold after WR
t
WHLH
RD or WR High to ALE High
Rev. A | Page 97 of 108
12.58 MHz Core Clock
Min
65
60
65
190
60
120
380
60
6.29 MHz Core Clock
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
Max
130
Min
130
120
135
375
120
250
755
125
Max
260
0
ALE (O)
PORT 2 (O)
t
WHLH
t
WLWH
t
LLWL
t
AVWL
t
LLAX
t
AVLL
t
QVWX
t
QVWH
t
WHQX
A0
A7
DATA
A16
A23
V8 A15
PSEN (O)
WR (O)
Figure 73. External Data Memory Write Cycle