ATtiny87 Atmel Corporation, ATtiny87 Datasheet - Page 7

• Manufacturer Part Number: ATtiny87
• Manufacturer: Atmel Corporation

Specifications of ATtiny87

• Flash (kbytes): 8 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 16
• Ext Interrupts: 16
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Lin: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 3
• Input Capture Channels: 1
• Pwm Channels: 9
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

2. AVR CPU Core
2.1
8265B–AVR–09/10
Overview
This section discusses the AVR core architecture in general. The main function of the CPU
core is to ensure correct program execution. The CPU must therefore be able to access mem-
ories, perform calculations, control peripherals, and handle interrupts.
Figure 2-1.
In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with
separate memories and buses for program and data. Instructions in the Program memory are
executed with a single level pipelining. While one instruction is being executed, the next
instruction is pre-fetched from the Program memory. This concept enables instructions to be
executed in every clock cycle. The Program memory is In-System Reprogrammable Flash
memory. The fast-access Register File contains 32 x 8-bit general purpose working registers
with a single clock cycle access time. This allows single-cycle Arithmetic Logic Unit (ALU)
operation. In a typical ALU operation, two operands are output from the Register File, the
operation is executed, and the result is stored back in the Register File – in one clock cycle.
Control Lines
Instruction
Instruction
Program
Memory
Register
Decoder
Flash
Block Diagram of the AVR Architecture
Program
Counter
and Control
EEPROM
Registrers
I/O Lines
Purpose
General
SRAM
Data Bus 8-bit
Status
32 x 8
Data
ALU
I/O Module1
Comparator
I/O Module 2
I/O Module n
Watchdog
Interrupt
Timer
A.D.C.
Analog
Unit
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