Figure 92, Atmega8515(l) – Rainbow Electronics ATmega8515L User Manual
Page 203
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203
ATmega8515(L)
2512A–AVR–04/02
Figure 91. External Memory Timing (SRWn1 = 1, SRWn0 = 0)
Figure 92. External Memory Timing (SRWn1 = 1, SRWn0 = 1)
Note:
1. The ALE pulse in the last period (T4-T7) is only present if the next instruction
accesses the RAM (internal or external).
ALE
T1
T2
T3
Wr
ite
Read
WR
T6
A15:8
Address
Prev. Addr.
DA7:0
Address
Data
Prev. Data
XX
RD
DA7:0 (XMBK = 0)
Data
Address
System Clock (CLK
CPU
)
1
4
2
7
6
3a
3b
5
8
12
16
13
10
11
14
15
9
T4
T5
ALE
T1
T2
T3
Wr
ite
Read
WR
T7
A15:8
Address
Prev. Addr.
DA7:0
Address
Data
Prev. Data
XX
RD
DA7:0 (XMBK = 0)
Data
Address
System Clock (CLK
CPU
)
1
4
2
7
6
3a
3b
5
8
12
16
13
10
11
14
15
9
T4
T5
T6
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