ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 385

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

External Data Memory Timing
Table 173. External Data Memory Characteristics, 4.5 - 5.5 Volts, No Wait-state
Notes:
Table 174. External Data Memory Characteristics, 4.5 - 5.5 Volts, 1 Cycle Wait-state
2549K–AVR–01/07
0
1
2
3a
3b
4
5
6
7
8
9
10
11
12
13
14
15
16
0
10
12
15
16
Symbol
1/t
t
t
t
t
RLDV
RLRH
DVWH
WLWH
Symbol
1/t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
LHLL
AVLL
LLAX_ST
LLAX_LD
AVLLC
AVRL
AVWL
LLWL
LLRL
DVRH
RLDV
RHDX
RLRH
DVWL
WHDX
DVWH
WLWH
1. This assumes 50% clock duty cycle. The half period is actually the high time of the external clock, XTAL1.
2. This assumes 50% clock duty cycle. The half period is actually the low time of the external clock, XTAL1.
CLCL
CLCL
Parameter
Oscillator Frequency
Read Low to Data Valid
RD Pulse Width
Data Valid to WR High
WR Pulse Width
Parameter
Oscillator Frequency
ALE Pulse Width
Address Valid A to ALE Low
Address Hold After ALE Low,
write access
Address Hold after ALE Low,
read access
Address Valid C to ALE Low
Address Valid to RD Low
Address Valid to WR Low
ALE Low to WR Low
ALE Low to RD Low
Data Setup to RD High
Read Low to Data Valid
Data Hold After RD High
RD Pulse Width
Data Setup to WR Low
Data Hold After WR High
Data Valid to WR High
WR Pulse Width
Min
240
240
240
8 MHz Oscillator
57.5
57.5
47.5
47.5
42.5
8 MHz Oscillator
Min
115
115
115
115
115
125
115
40
5
5
0
ATmega640/1280/1281/2560/2561
Max
67.5
67.5
75
Max
200
0.5t
0.5t
0.5t
0.5t
0.5t
1.0t
1.0t
1.0t
1.0t
1.0t
1.0t
1.0t
CLCL
CLCL
CLCL
CLCL
CLCL
Min
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
0.0
40
5
5
0
2.0t
2.0t
CLCL
Variable Oscillator
-15
-15
-20
2.0t
-5
-5
-10
-10
-10
-10
-10
-10
Min
CLCL
CLCL
0.0
(1)
(1)
(2)
(2)
(1)
Variable Oscillator
CLCL
-10
-10
0.5t
0.5t
1.0t
2.0t
CLCL
CLCL
Max
CLCL
16
Max
CLCL
16
+5
+5
-50
(2)
(2)
-50
Unit
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
MHz
Unit
ns
ns
ns
ns
385