ATTINY44A-SSN Atmel, ATTINY44A-SSN Datasheet - Page 116

• Manufacturer Part Number: ATTINY44A-SSN
• Description: IC MCU AVR 4KB FLASH 20MHZ 14SOI
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY44A-SSN

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 12
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• Processor Series: ATTINY4x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: SPI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 12
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

14. USI – Universal Serial Interface
14.1
14.2
116
Features
Overview
ATtiny24A/44A/84A
•
•
•
•
•
•
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
are listed in the
Figure 14-1.
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
latch between the output of the USI Data Register and the output pin, which delays the change
of data output to the opposite clock edge of the data input sampling. The serial input is always
sampled from the Data Input (DI) pin independent of the configuration.
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 of ATtiny24A/44A/84A” on page
“Register Descriptions” on page
USIDR
USIBR
USISR
USICR
Universal Serial Interface, Block Diagram
2
4-bit Counter
“Analog Comparator” on page
3
2
1
0
3
2
1
0
D Q
LE
[1]
2. Device-specific I/O Register and bit locations
123.
TIM0 COMP
Figure 14-1
0
1
Two-wire Clock
Control Unit
For actual placement of I/O pins
128). There is a transparent
CLOCK
HOLD
DO
DI/SDA
USCK/SCL
8183C–AVR–03/11
(Output only)
(Input/Open Drain)
(Input/Open Drain)