ST16C554DCQ-0A-EB Exar Corporation, ST16C554DCQ-0A-EB Datasheet - Page 14

• Manufacturer Part Number: ST16C554DCQ-0A-EB
• Description: EVAL BOARD FOR ST16C554D 64TQFP
• Manufacturer: Exar Corporation

Specifications of ST16C554DCQ-0A-EB

• Interface Type: UART
• Data Bus Width: 8 bit
• For Use With/related Products: ST16C554D
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ST16C554/554D
2.97V TO 5.5V QUAD UART WITH 16-BYTE FIFO
The 554 UART 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 10
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 HIGH or mark condition while RTS# and DTR# are de-asserted, and CTS#,
DSR# CD# and RI# inputs are ignored. Caution: the RX input must be held HIGH during loopback test else
upon exiting the loopback test the UART may detect and report a false “break” signal.
F
2.11
IGURE
10. I
Internal Loopback
shows how the modem port signals are re-configured. Transmit data from the transmit shift register
NTERNAL
L
OOP
B
ACK IN
Transmit Shift Register
Receive Shift Register
C
(THR/FIFO)
(RHR/FIFO)
HANNEL
A
RTS#
CTS#
DTR#
DSR#
CD#
AND
RI#
MCR bit-4=1
B
14
VCC
VCC
OP1#
OP2#
VCC
TX A-D
RX A-D
RTS# A-D
CTS# A-D
DTR# A-D
DSR# A-D
RI# A-D
CD# A-D
REV. 4.0.1