XR16L784 Exar Corporation, XR16L784 Datasheet - Page 16

• Manufacturer Part Number: XR16L784
• Description: High Performance 5V And 3.3V Quad Uart
• Manufacturer: Exar Corporation

XR16L784
HIGH PERFORMANCE 5V AND 3.3V QUAD UART
REV. 1.0.2
bit-4 = 1) an inverted IR-encoded input signal. This
option supports active low instead of normal active
Each UART channel provides an internal loopback
capability for system diagnostic purposes. The inter-
nal loopback mode is enabled by setting MCR regis-
ter bit-4 to logic 1. All regular UART functions operate
normally.
nals are re-configured. Transmit data from the trans-
4.4 I
NTERNAL
Figure 10
F
IGURE
L
OOPBACK
shows how the modem port sig-
9. I
Receive
IR Pulse
(RX pin)
RX Data
NFRARED
T X D ata
T ransm it
(T X P in)
IR P ulse
T
RANSMIT
0
Bit Time
B it T im e
0
1
1/16 Clock Delay
D
1
ATA
0
0
E
1
NCODING AND
C haracter
D ata B its
1
0
16
3/16 B it T im e
Data Bits
Character
high pulse from some infrared modules in the mar-
ket.
mit shift register output is internally routed to the re-
ceive shift register input allowing the system to re-
ceive the same data that it was sending. The TX pin
is held at logic 1 or mark condition while RTS# and
DTR# are de-asserted, and CTS#, DSR# CD# and
RI# inputs are ignored.
0
0
0
1
R
ECEIVE
1
1
1
0
D
0
ATA
1/2 B it T im e
1
1
D
IRdecoder-1
IrE ncoder-1
ECODING