ATA5771-PXQW Atmel, ATA5771-PXQW Datasheet - Page 130

• Manufacturer Part Number: ATA5771-PXQW
• Description: XMITTR UHF ASK/FSK 868MHZ 24VQFN
• Manufacturer: Atmel

Specifications of ATA5771-PXQW

• Frequency: 868MHz ~ 928MHz
• Modulation Or Protocol: UHF
• Power - Output: 8dBm
• Voltage - Supply: 2 V ~ 4 V
• Current - Transmitting: 9.8mA
• Data Interface: PCB, Surface Mount
• Memory Size: 4kB Flash, 256B EEPROM, 256B SRAM
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 24-VQFN Exposed Pad, 24-HVQFN, 24-SQFN, 24-DHVQFN
• Processor Series: ATA5x
• Core: AVR8
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 4 KB
• Data Ram Size: 256 B
• Interface Type: SPI, USI
• Maximum Clock Frequency: 4 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 12 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Applications: -
• Sensitivity: -
• Data Rate - Maximum: -
• Current - Receiving: -
• Lead Free Status / Rohs Status: Details

4.18.3.4
130
Atmel ATA5771/73/74
Two-wire Mode
The USI Two-wire mode is compliant to the Inter IC (TWI) bus protocol, but without slew rate
limiting on outputs and input noise filtering. Pin names used by this mode are SCL and SDA.
Figure 4-55. Two-wire Mode Operation, Simplified Diagram
Figure 4-55
Slave. It is only the physical layer that is shown since the system operation is highly depen-
dent of the communication scheme used. The main differences between the Master and Slave
operation at this level, is the serial clock generation which is always done by the Master, and
only the Slave uses the clock control unit. Clock generation must be implemented in software,
but the shift operation is done automatically by both devices. Note that only clocking on nega-
tive edge for shifting data is of practical use in this mode. The slave can insert wait states at
start or end of transfer by forcing the SCL clock low. This means that the Master must always
check if the SCL line was actually released after it has generated a positive edge.
Since the clock also increments the counter, a counter overflow can be used to indicate that
the transfer is completed. The clock is generated by the master by toggling the USCK pin via
the PORT Register.
The data direction is not given by the physical layer. A protocol, like the one used by the
TWI-bus, must be implemented to control the data flow.
SLAVE
MASTER
shows two USI units operating in Two-wire mode, one as Master and one as
Bit7
Bit7
Bit6
Bit6
Bit5
Bit5
Bit4
Bit4
Bit3
Bit3
Bit2
Bit2
Bit1
Bit1
Bit0
Bit0
Two-wire Clock
Control Unit
PORTxn
HOLD
SCL
SDA
SCL
SDA
SCL
VCC
9137E–RKE–12/10