xr16m698 Exar Corporation, xr16m698 Datasheet - Page 22

• Manufacturer Part Number: xr16m698
• Description: 1.62v To 3.63v High Performance Octal Uart With 32-byte Fifo
• Manufacturer: Exar Corporation

XR16M698
1.62V TO 3.63V HIGH PERFORMANCE OCTAL UART WITH 32-BYTE FIFO
Each UART channel provides an internal loopback capability for system diagnostic purposes. The internal
loopback mode is enabled by setting MCR register bit-4 to logic 1. All regular UART functions operate normally.
Figure 11
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 (HIGH),
and CTS#, DSR# CD# and RI# inputs are ignored.
2.16
Internal Loopback
shows how the modem port signals are re-configured. Transmit data from the transmit shift register
F
IGURE
11. I
NTERNAL
L
OOP
B
ACK
Transmit Shift
Receive Shift
Register
Register
22
RTS#
CTS#
DTR#
DSR#
RI#
CD#
MCR bit-4=1
OP1#
OP2#
VCC
VCC
VCC
TX [7:0]
RX [7:0]
RTS# [7:0]
CTS# [7:0]
DTR# [7:0]
DSR# [7:0]
RI# [7:0]
CD# [7:0]
REV. 1.0.0