architecture is more code efficient while achieving throughputs up to ten times faster than con-
ventional CISC microcontrollers.
The AT90USB82/162 provides the following features: 8K / 16K bytes of In-System Programma-
ble Flash with Read-While-Write capabilities, 512 bytes EEPROM, 512 bytes SRAM, 22 general
purpose I/O lines, 32 general purpose working registers, two flexible Timer/Counters with com-
pare modes and PWM, one USART, a programmable Watchdog Timer with Internal Oscillator,
an SPI serial port, debugWIRE interface, also used for accessing the On-chip Debug system
and programming and five software selectable power saving modes. The Idle mode stops the
CPU while allowing the SRAM, Timer/Counters, SPI port, and interrupt system to continue func-
tioning. The Power-down mode saves the register contents but freezes the Oscillator, disabling
all other chip functions until the next interrupt or Hardware Reset. In Standby mode, the Crys-
tal/Resonator Oscillator is running while the rest of the device is sleeping. This allows very fast
start-up combined with low power consumption. In Extended Standby mode, the main Oscillator
continues to run.
The device is manufactured using Atmel’s high-density nonvolatile memory technology. The on-
chip ISP Flash allows the program memory to be reprogrammed in-system through an SPI serial
interface, by a conventional nonvolatile memory programmer, or by an 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 AT90USB82/162 is a powerful microcontroller that provides a highly flexible and cost
effective solution to many embedded control applications.
The AT90USB82/162 AVR is supported with a full suite of program and system development
tools including: C compilers, macro assemblers, program debugger/simulators, in-circuit emula-
tors, and evaluation kits.
2.2 Pin Descriptions
Digital supply voltage.
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 serves the functions of various special features of the AT90USB82/162 as listed on