Datasheet

73
2490R–AVR–02/2013
ATmega64(L)
Alternate Functions of
Port A
The Port A has an alternate function as the address low byte and data lines for the External
Memory Interface.
Table 28 and Table 29 relates the alternate functions of Port A to the overriding signals shown in
Figure 33 on page 71.
Table 27. Port A Pins Alternate Functions
Port Pin Alternate Function
PA7 AD7 (External memory interface address and data bit 7)
PA6 AD6 (External memory interface address and data bit 6)
PA5 AD5 (External memory interface address and data bit 5)
PA4 AD4 (External memory interface address and data bit 4)
PA3 AD3 (External memory interface address and data bit 3)
PA2 AD2 (External memory interface address and data bit 2)
PA1 AD1 (External memory interface address and data bit 1)
PA0 AD0 (External memory interface address and data bit 0)
Table 28. Overriding Signals for Alternate Functions in PA7..PA4
Signal
Name PA7/AD7 PA6/AD6 PA5/AD5 PA4/AD4
PUOE
SRE SRE SRE SRE
PUOV
~(WR | ADA
(1)
) •
PORTA7 • PUD
~(WR | ADA) •
PORTA6 • PUD
~(WR | ADA) •
PORTA5 • PUD
~(WR | ADA) •
PORTA4 • PUD
DDOE
SRE SRE SRE SRE
DDOV
WR | ADA WR | ADA WR | ADA WR | ADA
PVOE
SRE SRE SRE SRE
PVOV
A7 • ADA | D7
OUTPUT • WR
A6 • ADA | D6
OUTPUT • WR
A5 • ADA | D5
OUTPUT • WR
A4 • ADA | D4
OUTPUT • WR
DIEOE
0000
DIEOV
0000
DI
D7 INPUT D6 INPUT D5 INPUT D4 INPUT
AIO
––––