at43usb355 ATMEL Corporation, at43usb355 Datasheet - Page 66

• Manufacturer Part Number: at43usb355
• Description: At43usb355 Full-speed Usb Microcontroller With Embedded Hub, Adc And Pwm
• Manufacturer: ATMEL Corporation

ADC Characteristics
I/O-Ports
Port A
66
AT43USB355
All AVR ports have true Read-Modify-Write functionality when used as general digital I/O
ports. This means that the direction of one port pin can be changed without unintentionally
changing the direction of any other pin with the SBI and CBI instructions. The same applies for
changing drive value if configured as output or enabling/disabling of pull-up resistors if config-
ured as input.
In the AT43USB355E, Port F[0:4] are used as the SPI signals for the external serial EEPROM.
Once the data from the SEEPROM are loaded to the SRAM, Port F[1:3] become available as
GPIO pins. Only cycling the power to the chip off and on again will temporarily assign these
pins as SEEPROM interface signals.
Port A is an 8-bit bi-directional I/O port. The Port A output buffers can sink or source 2 mA.
Three I/O memory address locations are allocated for the Port A, one each for the Data Regis-
ter PORTA, $1B($3B), Data Direction Register (DDRA), $1A($3A) and the Port A Input Pins
(PINA) $19($39). The Port A Input Pins address is read only, while the Data Register and the
Data Direction Register are read/write.
All port pins have individually selectable pull-up resistors. When pins PA0 to PA7 are used as
inputs and are externally pulled low, they will source current if the internal pull-up resistors are
activated.
Symbol
V
REF
Parameter
Resolution
Integral Non-linearity
Differential Non-linearity
Zero Error (Offset)
Full Scale Error
Reference Voltage
V
Analog Input Resistance
Conversion Time
Clock Frequency
REF
input resistance
Condition
25°C
V
V
at 50% duty cycle
REF
REF
= VCEXTA
= VCEXTA
Min
2.4
12
12
-2
-4
Typ
100
10
18
VCEXTA
Max
768
24
4
4
2
4
1
2603G–USB–04/06
MHz
Unit
LSB
LSB
LSB
LSB
Bits
MΩ
kΩ
µs
V
s