xr16m654 Exar Corporation, xr16m654 Datasheet - Page 23

• Manufacturer Part Number: xr16m654
• Description: 1.62v To 3.63v Quad Uart With 64-byte Fifo
• Manufacturer: Exar Corporation

REV. 1.0.0
The M654 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.
F
2.16
IGURE
13. I
Infrared Mode
NFRARED
T
RANSMIT
TX Data
Transmit
(TX Pin)
IR Pulse
Receive
IR Pulse
(RX pin)
RX Data
D
ATA
0
E
Bit Time
NCODING AND
Bit Time
0
1
1/16 Clock Delay
1
Figure 13
Figure
0
0
1
Character
13.
Data Bits
1
R
23
0
below.
ECEIVE
Data Bits
Character
3/16 Bit Time
1.62V TO 3.63V QUAD UART WITH 64-BYTE FIFO
0
0
0
D
1
ATA
1
1
D
1
ECODING
0
0
1
1/2 Bit Time
1
IRdecoder-1
IrEncoder-1
XR16M654/654D