ATA5771-DK1 Atmel, ATA5771-DK1 Datasheet - Page 125

• Manufacturer Part Number: ATA5771-DK1
• Description: BOARD XMITTER FOR ATA5771 868MHZ
• Manufacturer: Atmel
• Type: Transmitterr

Specifications of ATA5771-DK1

• Frequency: 868MHz
• Maximum Frequency: 868 MHz
• Supply Voltage (max): 4 V
• Supply Voltage (min): 2 V
• Supply Current: 8.5 mA
• Product: RF Development Tools
• For Use With/related Products: ATA5771
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.18
4.18.1
4.18.2
9137E–RKE–12/10
USI – Universal Serial Interface
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. Inter-
rupts are included to minimize the processor load.
A simplified block diagram of the USI is shown in
pins. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The
device-specific I/O Register and bit locations are listed in the
tion” on page
Figure 4-52. 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.
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
39.
USIDR
USISR
USICR
2
4-bit Counter
3
2
1
0
3
2
1
0
D Q
LE
[1]
TIM0 COMP
Figure
0
1
Atmel ATA5771/73/74
4-52. For the actual placement of I/O
Two-wire Clock
Control Unit
Section 4.9.10 “Register Descrip-
CLOCK
HOLD
DO
DI/SDA
USCK/SCL
(Output only)
(Input/Open Drain)
(Input/Open Drain)
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