3)The sum of all IOH, for ports G3-G4, B0-B7, H0-H7 should not exceed 200 mA.
4)The sum of all IOH, for ports E0-E7, G5 should not exceed 100 mA.
5)The sum of all IOH, for ports F0-F7, K0-K7 should not exceed 100 mA.
If IOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current
greater than the listed test condition.
5. Values with “PRR1 – Power Reduction Register 1” enabled (0xFF).
31.2 Speed Grades
Maximum frequency is depending on VCC. As shown in Figure 31-1 trough Figure 31-4, the Max-
imum Frequency vs. VCC curve is linear between 1.8V < VCC < 2.7V and between 2.7V < VCC
4.5V.
<
31.2.1
8 MHz
Figure 31-1. Maximum Frequency vs. VCC, ATmega640V/1280V/1281V/2560V/2561V
8 MHz
4 MHz
Safe Operating Area
1.8V
2.7V
5.5V
Figure 31-2. Maximum Frequency vs. VCC when only using No-Read-While-Write Section(1),
ATmega2560V/ATmega2561V
8 MHz
Safe Operating Area
2 MHz
1.8V
2.7V
5.5V
Note:
1. When only using the Read-While-Write Section of the program memory, a higher speed can
be achieved at low voltage, see “Read-While-Write and No Read-While-Write Flash Sections”
on page 318 for addresses.
372
ATmega640/1280/1281/2560/2561
2549L–AVR–08/07
ATMEL [ ATMEL ]
