AT90USB1286-16MU ATMEL [ATMEL Corporation], AT90USB1286-16MU Datasheet - Page 80

• Manufacturer Part Number: AT90USB1286-16MU
• Description: Microcontroller with 64/128K Bytes of ISP Flash and USB Controller
• Manufacturer: ATMEL [ATMEL Corporation]

10.3.1
10.3.2
80
AT90USB64/128
MCU Control Register – MCUCR
Alternate Functions of Port A
• Bit 4 – PUD: Pull-up Disable
When this bit is written to one, the pull-ups in the I/O ports are disabled even if the DDxn and
PORTxn Registers are configured to enable the pull-ups ({DDxn, PORTxn} = 0b01). See
figuring the Pin” on page 74
The Port A has an alternate function as the address low byte and data lines for the External
Memory Interface.
Table 10-3.
Table 10-4
shown in
Table 10-4.
Bit
Read/Write
Initial Value
Signal
Name
PUOE
PUOV
DDOE
DDOV
PVOE
PVOV
DIEOE
DIEOV
DI
AIO
Port Pin
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
Figure 10-5 on page
PA7/AD7
SRE
~(WR | ADA
PORTA7 • PUD
SRE
WR | ADA
SRE
A7 • ADA | D7
OUTPUT • WR
0
0
D7 INPUT
–
7
JTD
R/W
0
and
Port A Pins Alternate Functions
Overriding Signals for Alternate Functions in PA7..PA4
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)
Table 10-5
6
–
R
0
(1)
) •
for more details about this feature.
relates the alternate functions of Port A to the overriding signals
5
–
R
0
PA6/AD6
~(WR | ADA) •
PORTA6 • PUD
SRE
WR | ADA
SRE
A6 • ADA | D6
OUTPUT • WR
0
0
D6 INPUT
–
SRE
78.
R/W
4
PUD
0
3
–
R
0
PA5/AD5
SRE
~(WR | ADA) •
PORTA5 • PUD
SRE
WR | ADA
SRE
A5 • ADA | D5
OUTPUT • WR
0
0
D5 INPUT
–
2
–
R
0
1
IVSEL
R/W
0
PA4/AD4
SRE
~(WR | ADA) •
PORTA4 • PUD
SRE
WR | ADA
SRE
A4 • ADA | D4
OUTPUT • WR
0
0
D4 INPUT
–
0
IVCE
R/W
0
MCUCR
7593A–AVR–02/06
“Con-