xr17v258 Exar Corporation, xr17v258 Datasheet - Page 35

• Manufacturer Part Number: xr17v258
• Description: 66mhz Pci Bus Octal Uart With Power Management Support
• Manufacturer: Exar Corporation

xr
REV. 1.0.0
The infrared decoder receives the input pulse from the infrared sensing diode on RX pin. Each time the
decoder senses a light pulse, it returns a "0" to the data bit stream. The RX input signal may be inverted prior
delivered to the input of the decoder via internal register setting. This option supports active LOW instead of
normal active HIGH pulse from some infrared modules on the market.
Each UART channel provides an internal loopback capability for system diagnostic. The internal loopback
mode is enabled by setting MCR register bit [4] to a logic 1. All regular UART functions operate normally.
Figure 14
output is internally routed to the receive shift register input allowing the system to receive the same data that it
was sending. The TX pin is held at HIGH or mark condition while RTS# and DTR# are de-asserted. The CTS#,
DSR#, CD# and RI# inputs are ignored.
4.4
Internal Loopback
shows how the modem port signals are re-configured. Transmit data from the transmit shift register
F
IGURE
Receive
IR Pulse
(RX pin)
RX Data
TX Data
Transmit
(TX Pin)
IR Pulse
13. I
NFRARED
66MHZ PCI BUS OCTAL UART WITH POWER MANAGEMENT SUPPORT
0
Bit Time
Bit Time
0
1
1/16 Clock Delay
T
RANSMIT
1
0
0
1
Character
Data Bits
D
1
ATA
0
35
Data Bits
3/16 Bit Time
Character
0
E
0
NCODING AND
0
1
1 1
1
0
R
0
ECEIVE
1/2 Bit Time
1
1
IRdecoder-
IrEncoder-1
D
ATA
D
ECODING
XR17V258