Datasheet

Table Of Contents
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ATmega640/V-1280/V-1281/V-2560/V-2561/V [DATASHEET]
2549Q–AVR–02/2014
Figure 9-4. External Data Memory Cycles with SRWn1 = 0 and SRW n0 = 1
(1)
Note: 1. SRWn1 = SRW11 (upper sector) or SRW01 (lower sector), SRWn0 = SRW10 (upper sector) or SRW00 (lower sec-
tor).
The ALE pulse in period T5 is only present if the next instruction accesses the RAM (internal or external).
Figure 9-5. External Data Memory Cycles with SRWn1 = 1 and SRW n0 = 0
(1)
Note: 1. SRWn1 = SRW11 (upper sector) or SRW01 (lower sector), SRWn0 = SRW10 (upper sector) or SRW 00 (lower sec-
tor).
The ALE pulse in period T6 is only present if the next instruction accesses the RAM (internal or external).
ALE
T1 T2 T3
Write
Read
WR
T6
A15:8
AddressPrev. addr.
DA7:0
Address DataPrev. data XX
RD
DA7:0 (XMBK = 0)
DataPrev. data Address
DataPrev. data Address
DA7:0 (XMBK = 1)
System Clock (CLK
CPU
)
T4 T5