ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 91

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

Alternate Functions of Port A
2549K–AVR–01/07
The Port A has an alternate function as the address low byte and data lines for the
External Memory Interface.
Table 39. Port A Pins Alternate Functions
Table 40 and Table 41 relates the alternate functions of Port A to the overriding signals
shown in Figure 36 on page 89.
Table 40. Overriding Signals for Alternate Functions in PA7:PA4
Note:
Signal
Name
PUOE
PUOV
DDOE
DDOV
PVOE
PVOV
DIEOE
DIEOV
DI
AIO
Port Pin
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
1. ADA is short for ADdress Active and represents the time when address is output. See
PA7/AD7
SRE
~(WR | ADA
PORTA7 • PUD
SRE
WR | ADA
SRE
A7 • ADA | D7
OUTPUT • WR
0
0
D7 INPUT
–
“External Memory Interface” on page 26 for details.
Alternate Function
AD7 (External memory interface address and data bit 7)
AD6 (External memory interface address and data bit 6)
AD5 (External memory interface address and data bit 5)
AD4 (External memory interface address and data bit 4)
AD3 (External memory interface address and data bit 3)
AD2 (External memory interface address and data bit 2)
AD1 (External memory interface address and data bit 1)
AD0 (External memory interface address and data bit 0)
(1)
) •
ATmega640/1280/1281/2560/2561
PA6/AD6
SRE
~(WR | ADA) •
PORTA6 • PUD
SRE
WR | ADA
SRE
A6 • ADA | D6
OUTPUT • WR
0
0
D6 INPUT
–
PA5/AD5
SRE
~(WR | ADA) •
PORTA5 • PUD
SRE
WR | ADA
SRE
A5 • ADA | D5
OUTPUT • WR
0
0
D5 INPUT
–
PA4/AD4
SRE
~(WR | ADA) •
PORTA4 • PUD
SRE
WR | ADA
SRE
A4 • ADA | D4
OUTPUT • WR
0
0
D4 INPUT
–
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