Rainbow Electronics AT90C8534 - Manual (Page 3)

AT90C8534
3
The AVR core combines a rich instruction set with 32 general-purpose working registers. All the 32 registers are directly
connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction
executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times
faster than conventional CISC microcontrollers.
The AT90C8534 provides the following features: 8K bytes of programmable Flash, 512 bytes EEPROM, 256 bytes SRAM,
7 general output lines, 2 external interrupt lines, 32 general-purpose working registers, 2 flexible timer/counters, internal
and external interrupts, 6-channel, 10-bit ADC, and 2 software-selectable power saving modes. The Idle mode stops the
CPU while allowing the ADC, timer/counters and interrupt system to continue functioning. The Power-down mode saves
the SRAM and register contents but freezes the oscillator, disabling all other chip functions until the next interrupt or hard-
ware reset.
The device is manufactured using Atmel’s high-density nonvolatile memory technology. The on-chip programmable Flash
allows the program memory to be reprogrammed by a conventional nonvolatile memory programmer. By combining an
8-bit RISC CPU with programmable Flash on a monolithic chip, the Atmel AT90C8534 is a powerful microcontroller that
provides a highly flexible and cost-effective solution to many embedded control applications.
The AT90C8534 AVR is supported with a full suite of program and system development tools including: C compilers, macro
assemblers, program debugger/simulators, in-circuit emulators and evaluation kits.
Pin Descriptions
VCC
Digital supply voltage
GND
Digital ground
Port A (PA6..PA0)
Port A is a 7-bit output port with tri-state mode. The Port A output buffers can sink 20 mA and can drive LED displays
directly. The port pins are tri-stated when a reset condition becomes active, even if the clock is not running.
INT1, 0
External interrupt input pins. A falling or rising edge on either of these pins will generate an interrupt request. Interrupt
pulses longer than 40 ns will generate an interrupt, even if the clock is not running.
ADIN5..0
ADC input pins. Any of these pins can be selected as the input to the ADC.
RESET
Reset input. An external reset is generated by a low level on the RESET pin. Reset pulses longer than 100 ns will generate
a reset, even if the clock is not running. Shorter pulses are not guaranteed to generate a reset.
XTAL1
Input to the inverting oscillator amplifier and input to the internal clock operating circuit.
XTAL2
Output from the inverting oscillator amplifier
AVCC
This is the supply voltage pin for the A/D Converter. If the ADC is not used, the pin must be connected to V
CC
. If the ADC is
used, the pin should be connected to VCC via a low-pass filter. See page 30 for details on operation of the ADC.
AGND
Analog ground. If the board has a separate analog ground plane, this pin should be connected to this ground plane.
Otherwise, connect to GND.