xr16l2552im Exar Corporation, xr16l2552im Datasheet - Page 18

• Manufacturer Part Number: xr16l2552im
• Description: Industry Smallest Package Uart With 2.25v To 5.5v Operation
• Manufacturer: Exar Corporation

XR16L2552
2.25V TO 5.5V DUART WITH 16-BYTE FIFO
The L2552 UART includes the infrared encoder and decoder compatible to the IrDA (Infrared Data
Association) version 1.0. 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. 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’. When the infrared feature
is enabled, the transmit data output, TX, idles at logic zero level. Likewise, the RX input assumes an idle level
of logic zero from a reset and power up, see
Typically, 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.
2.18
Infrared Mode
F
IGURE
Receive
IR Pulse
(RX pin)
RX Data
TX Data
Transmit
IR Pulse
(TX Pin)
12. I
NFRARED
0
Bit Time
Bit Time
0
1
1/16 Clock Delay
T
RANSMIT
1
0
Figure
0
1
Character
Data Bits
12.
D
1
ATA
0
18
3/16 Bit Time
Data Bits
Character
0
E
0
Figure 12
NCODING AND
0
1
1 1
1
below.
0
R
0
ECEIVE
1/2 Bit Time
1
1
IRdecoder-
IrEncoder-1
D
ATA
D
ECODING
xr
REV. 1.1.1