ATTINY85-15ST1 Atmel, ATTINY85-15ST1 Datasheet - Page 96

• Manufacturer Part Number: ATTINY85-15ST1
• Description: MCU AVR 8K FLASH 15MHZ 8-SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY85-15ST1

• Package / Case: 8-SOIC (3.9mm Width)
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 105°C
• Speed: 16MHz
• Number Of I /o: 6
• Eeprom Size: 512 x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Program Memory Size: 8KB (8K x 8)
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: USI
• Core Size: 8-Bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

16. Universal Serial Interface – USI
16.1
96
Overview
ATtiny25/45/85
The Universal Serial Interface, or 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. The main features of the USI are:
•
•
•
•
•
•
A simplified block diagram of the USI is shown on Figure 16-1. For the actual placement of I/O
pins, refer to
bits and I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed
in the
Figure 16-1. Universal Serial Interface, Block Diagram
The 8-bit Shift Register is directly accessible via the data bus and contains the incoming and
outgoing data. The register has no buffering so the data must be read as quickly as possible to
ensure that no data is lost. The most significant bit is connected to one of two output pins
depending of the wire mode configuration. A transparent latch is inserted between the Serial
Register Output and 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.
The 4-bit counter can be both read and written via the data bus, and can generate an overflow
interrupt. Both the Serial Register and the counter are clocked simultaneously by the same clock
source.
Two-wire Synchronous Data Transfer (Master or Slave, f
Three-wire Synchronous Data Transfer (Master or Slave f
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
“USI Register Descriptions” on page
“Pinout ATtiny25/45/85” on page
USIDR
USIDB
USISR
USICR
2
4-bit Counter
3
2
1
0
3
2
1
0
D Q
LE
103.
[1]
2. CPU accessible I/O Registers, including I/O
TIM0 COMP
0
1
SCLmax
SCKmax
Two-wire Clock
Control Unit
= f
= f
CK
CK
/16)
CLOCK
/4)
HOLD
DO
DI/SDA
USCK/SCL
(Output only)
(Input/Open Drain)
(Input/Open Drain)
7598H–AVR–07/09