ATtiny24 Atmel Corporation, ATtiny24 Datasheet - Page 117

• Manufacturer Part Number: ATtiny24
• Manufacturer: Atmel Corporation

Specifications of ATtiny24

• Flash (kbytes): 2 Kbytes
• Pin Count: 14
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 4
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 12
• Ext Interrupts: 12
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.12
• Eeprom (bytes): 128
• 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: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

14. USI – Universal Serial Interface
14.1
14.2
8006K–AVR–10/10
Features
Overview
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The Universal Serial Interface (USI), provides the basic hardware resources needed for serial
communication. Combined with a minimum of control software, the USI allows significantly
higher transfer rates and uses less code space than solutions based on software only. Interrupts
are included to minimize the processor load.
A simplified block diagram of the USI is shown in
refer to
listed in the
Figure 14-1. Universal Serial Interface, Block Diagram
The 8-bit USI Data Register (USIDR) contains the incoming and outgoing data. It is directly
accessible via the data bus but a copy of the contents is also placed in the USI Buffer Register
(USIBR) where it can be retrieved later. If reading the USI Data Register directly, the register
must be read as quickly as possible to ensure that no data is lost.
The most significant bit of the USI Data Register is connected to one of two output pins (depend-
ing on the mode configuration, see
transparent latch between the output of the USI Data Register and the output pin, which delays
Two-wire Synchronous Data Transfer (Master or Slave)
Three-wire Synchronous Data Transfer (Master or Slave)
Data Received Interrupt
Wakeup from Idle Mode
In Two-wire Mode: Wake-up from All Sleep Modes, Including Power-down Mode
Two-wire Start Condition Detector with Interrupt Capability
“Pinout ATtiny24/44/84” on page
“Register Descriptions” on page
USIDR
USICR
USIDB
USISR
2
4-bit Counter
“USICR – USI Control Register” on page
3
2
1
0
3
2
1
0
D Q
LE
2. Device-specific I/O Register and bit locations are
124.
[1]
TIM0 COMP
Figure 14-1
0
1
Two-wire Clock
Control Unit
For actual placement of I/O pins
ATtiny24/44/84
CLOCK
HOLD
DO
DI/SDA
USCK/SCL
126). There is a
(Output only)
(Input/Open Drain)
(Input/Open Drain)
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