ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 389

• Manufacturer Part Number: ATMEGA2561V
• Description: 8-bit Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

2549K–AVR–01/07
Figure 165. External Memory Timing (SRWn1 = 1, SRWn0 = 0)
Figure 166. External Memory Timing (SRWn1 = 1, SRWn0 = 1)
The ALE pulse in the last period (T4-T7) is only present if the next instruction accesses the RAM
(internal or external).
System Clock (CLK
System Clock (CLK
DA7:0 (XMBK = 0)
DA7:0 (XMBK = 0)
DA7:0
A15:8
CPU
ALE
WR
DA7:0
A15:8
RD
CPU
ALE
WR
)
RD
)
Prev. addr.
Prev. data
Prev. addr.
Prev. data
T1
T1
1
ATmega640/1280/1281/2560/2561
Address
Address
4
2
1
5
T2
6
Address
Address
3a
3b
4
2
XX
7
5
8
T2
6
13
3a
3b
XX
10
7
8
13
T3
10
T3
Data
Address
12
Data
16
15
T4
9
Data
Address
12
Data
16
15
T4
9
T5
11
T5
()
T6
11
14
T6
14
T7
389