Rainbow Electronics ATmega128RFA1 - Manual (Page 5)

5
8266A-MCU Wireless-12/09
ATmega128RFA1
trough an SPI serial interface, by a conventional nonvolatile memory programmer, or by
on on-chip boot program running on the AVR core. The boot program can use any
interface to download the application program in the application Flash memory.
Software in the boot Flash section will continue to run while the application Flash
section is updated, providing true Read-While-Write operation. By combining an 8 bit
RISC CPU with In-System Self-Programmable Flash on a monolithic chip, the Atmel
ATmega128RFA1 is a powerful microcontroller that provides a highly flexible and cost
effective solution to many embedded control applications.
The ATmega128RFA1 AVR is supported with a full suite of program and system
development
tools including: C compiler, macro assemblers, program
debugger/simulators, in-circuit emulators, and evaluation kits.
3.2 Pin Descriptions
3.2.1 EVDD
External analog supply voltage;
3.2.2 DEVDD
External digital supply voltage;
3.2.3 AVDD
Regulated analog supply voltage (internally generated);
3.2.4 DVDD
Regulated digital supply voltage (internally generated);
3.2.5 DVSS
Digital ground;
3.2.6 AVSS
Analog ground;
3.2.7 Port B (PB7...PB0)
Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port B output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port B pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
Port B also provides functions of various special features of the ATmega128RFA1.
3.2.8 Port D (PD7...PD0)
Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port D output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port D pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port D pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
Port D also provides functions of various special features of the ATmega128RFA1.
3.2.9 Port E (PE7...PE0)
Port E is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port E output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port E pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port E pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
Port E also provides functions of various special features of the ATmega128RFA1.