SX1212IWLTRT Semtech, SX1212IWLTRT Datasheet - Page 38

• Manufacturer Part Number: SX1212IWLTRT
• Description: IC TXRX 300MHZ-510MHZ 32-TQFN
• Manufacturer: Semtech

Specifications of SX1212IWLTRT

• Frequency: 300MHz ~ 510MHz
• Data Rate - Maximum: 150kbps
• Modulation Or Protocol: FSK, OOK
• Applications: AMR, ISM, Home Automation, Process Control
• Power - Output: 12.5dBm
• Sensitivity: -110dBm
• Voltage - Supply: 2.1 V ~ 3.6 V
• Current - Receiving: 3mA
• Current - Transmitting: 25mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TQFN
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Modulation Type: FSK/OOK
• Package Type: TQFN EP
• Operating Supply Voltage (min): 2.1V
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 3.6V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed
• Other names: SX1212IWLTR

To read bytes from the FIFO the timing diagram below should be carefully followed by the uC.
Note that it is compulsory to toggle NSS_DATA back high between each byte read.
In Buffered and Packet modes of operation, both data to be transmitted and that has been received are stored in a
configurable FIFO (First In First Out) device. It is accessed via the SPI Data interface and provides several
interrupts for transfer management.
The FIFO is 1 byte (8 bits) wide hence it only performs byte (parallel) operations, whereas the demodulator
functions serially. A shift register is therefore employed to interface the two devices. In transmit mode it takes bytes
from the FIFO and outputs them serially (MSB first) at the programmed bit rate to the modulator. Similarly, in Rx the
shift register gets bit by bit data from the demodulator and writes them byte by byte to the FIFO. This is illustrated in
figure below.
The FIFO width is programmable, to 16, 32, 48 or 64 bytes via MCParam_Fifo_size
Rev 2 – June 18th, 2009
ADVANCED COMMUNICATIONS & SENSING
Read Byte (after/during Rx)
NSS_DATA (In)
SCK (In)
MOSI (In)
MISO (Out)
5.2.2. FIFO
HZ
5.2.2.1. Overview and Shift Register (SR)
5.2.2.2. Size Selection
D1(7)
1
x
D1(6) D1(5)
x
2
x
3
Data Tx/Rx
1
Figure 30: Read Bytes Sequence (ex: 2 bytes)
D1(4) D1(3)
st
4
x
byte read
Figure 31: FIFO and Shift Register (SR)
5
x
1
D1(2) D1(1)
6
x
MSB
7
x
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D1(0)
8
x
SR (8bits)
x
byte0
byte1
HZ
8
D2(7) D2(6)
1
x
2
x
LSB
D2(5)
3
x
FIFO
2
D2(4)
nd
4
x
byte read
D2(3)
5
x
D2(2)
6
x
D2(1)
7
x
D2(0)
8
x
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SX1212
HZ