XR16V698 datasheet(21/58 Pages) EXAR

Part #	XR16V698

Description	2.25V TO 3.6V HIGH PERFORMANCE OCTAL UART WITH 32-BYTE FIFO

PDF	58 Pages

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Manufacturer	EXAR [Exar Corporation]

Direct Link	http://www.exar.com

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XR16V698

REV. 1.0.3

2.25V TO 3.6V HIGH PERFORMANCE OCTAL UART WITH 32-BYTE FIFO

2.16

Internal Loopback

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

shows how the modem port signals are re-configured. Transmit data from the transmit shift register

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.

FIGURE 11. INTERNAL LOOP BACK

TX [7:0]

RX [7:0]

RTS# [7:0]

MCR bit-4=1

VCC

Transmit Shift

Receive Shift

CTS# [7:0]

DTR# [7:0]

DSR# [7:0]

RI# [7:0]

CD# [7:0]

OP1#

OP2#

RTS#

CTS#

DTR#

DSR#

RI#

CD#

XR16V698 Datasheet(PDF) 21 Page - Exar Corporation