XR20M1172IL32-F Exar Corporation, XR20M1172IL32-F Datasheet - Page 22

• Manufacturer Part Number: XR20M1172IL32-F
• Description: IC UART FIFO I2C/SPI 64B 32QFN
• Manufacturer: Exar Corporation

Specifications of XR20M1172IL32-F

• Number Of Channels: 2, DUART
• Package / Case: 32-VFQFN Exposed Pad
• Features: *
• Fifo's: 64 Byte
• Protocol: RS485
• Voltage - Supply: 1.62 V ~ 3.63 V
• With Auto Flow Control: Yes
• With Irda Encoder/decoder: Yes
• With False Start Bit Detection: Yes
• With Modem Control: Yes
• With Cmos: Yes
• Mounting Type: Surface Mount
• Data Rate: 16 Mbps
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 1.62 V
• Supply Current: 250 uA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• No. Of Channels: 2
• Uart Features: Tx/Rx FIFO Counters
• Supply Voltage Range: 1.62V To 3.63V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: QFN
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

XR20M1172
TWO CHANNEL I2C/SPI UART WITH 64-BYTE FIFO
The M1172 UART includes the infrared encoder and decoder compatible to the IrDA (Infrared Data
Association) version 1.0 and 1.1. The IrDA 1.0 standard that stipulates the infrared encoder sends out a 3/16 of
a bit wide HIGH-pulse for each “0” bit in the transmit data stream with a data rate up to 115.2 Kbps. For the
IrDA 1.1 standard, the infrared encoder sends out a 1/4 of a bit time wide HIGH-pulse for each "0" bit in the
transmit data stream with a data rate up to 1.152 Mbps. This signal encoding reduces the on-time of the
infrared LED, hence reduces the power consumption. See
The infrared encoder and decoder are enabled by setting MCR register bit-6 to a ‘1’. With this bit enabled, the
infrared encoder and decoder is compatible to the IrDA 1.0 standard. For the infrared encoder and decoder to
be compatible to the IrDA 1.1 standard, EFCR bit-7 will also need to be set to a ’1’. When the infrared feature
is enabled, the transmit data output, TX, idles LOW. Likewise, the RX input also idles LOW, see
The wireless infrared decoder receives the input pulse from the infrared sensing diode on the RX pin. Each
time it senses a light pulse, it returns a logic 1 to the data bit stream.
The UART can be in the infrared mode upon power-up if the ENIR# pin is LOW. After power-up, the infrared
mode can be controlled via MCR bit-6.
2.15
Infrared Mode
F
IGURE
TX Data
Transmit
Receive
IR Pulse
(RX pin)
RX Data
IR Pulse
(TX Pin)
18. I
NFRARED
0
Bit Time
1
Bit Time
0
T
1/16 Clock Delay
RANSMIT
0
1
0
1
Character
Data Bits
D
1
0
Data Bits
ATA
Character
22
3/16 or 1/4
Bit Time
0
0
E
Figure 18
NCODING AND
0
1
1 1
1
below.
0
R
0
ECEIVE
1
1/2 Bit Time
1
IRdecoder-1
IrEncoder-1
D
ATA
D
ECODING
Figure
REV. 1.0.1
18.