XR17C158 Exar Corporation, XR17C158 Datasheet - Page 25

• Manufacturer Part Number: XR17C158
• Description: Eight-channel Pci-based (UART)
• Manufacturer: Exar Corporation

XR17C158
REV. 1.0.0
delivered to the input of the decoder. This option sup-
ports 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 loop-
back mode is enabled by setting MCR register bit-4 to
logic 1. All regular UART functions operate normally.
Figure 11
configured. Transmit data from the transmit shift reg-
4.4 I
NTERNAL
shows how the modem port signals are re-
F
IGURE
PCI BUS OCTAL UART
L
Receive
IR Pulse
(RX pin)
RX Data
OOPBACK
TX Data
Transmit
IR Pulse
(TX Pin)
10. I
NFRARED
0
Bit Time
1
T
RANSMIT
Bit Time
0
0
1/16 Clock Delay
1
1
D
Character
Data Bits
ATA
0
0
3/16 Bit Time
E
NCODING AND
1
0
25
Data Bits
Character
1
ister output is internally routed to the receive shift reg-
ister input allowing the system to receive the same
data that it was sending. The TX pin is held at logic 1
or mark condition while RTS# and DTR# are de-as-
serted, and CTS#, DSR# CD# and RI# inputs are ig-
nored.
0
1
0
0
R
ECEIVE
1
1
1/2 Bit Time
1
IrEncoder-
D
ATA
0
D
ECODING
1
IRdecoder-
PRELIMINARY