sc68c2550b NXP Semiconductors, sc68c2550b Datasheet - Page 6

• Manufacturer Part Number: sc68c2550b
• Description: Sc68c2550b 5 V, 3.3 V And 2.5 V Dual Uart, 5 Mbit/s Max. , With 16-byte Fifos And Motorola Up Interface
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Table 2:
9397 750 14941
Product data sheet
Symbol
DTRA,
DTRB
RIA, RIB
RTSA,
RTSB
RXA, RXB 5, 4
TXA, TXB 7, 8
n.c.
Pin description
Pin
34, 35
41, 21
33, 22
12, 25, 29,
37
Type
O
I
O
I
O
-
…continued
Description
Data Terminal REady (active LOW). These outputs are associated with individual UART
channels, A through B. A logic 0 on this pin indicates that the SC68C2550B is
powered-on and ready. This pin can be controlled via the modem control register. Writing
a logic 1 to MCR[0] will set the DTR output to logic 0, enabling the modem. This pin will
be a logic 1 after writing a logic 0 to MCR[0], or after a reset. This pin has no effect on the
UART’s transmit or receive operation.
Ring Indicator (active LOW). These inputs are associated with individual UART
channels, A through B. A logic 0 on this pin indicates the modem has received a ringing
signal from the telephone line. A logic 1 transition on this input pin will generate an
interrupt.
Request to Send (active LOW). These outputs are associated with individual UART
channels, A through B. A logic 0 on the RTS pin indicates the transmitter has data ready
and waiting to send. Writing a logic 1 in the modem control register MCR[1] will set this
pin to a logic 0, indicating data is available. After a reset this pin will be set to a logic 1.
This pin has no effect on the UART’s transmit or receive operation.
Receive data A, B. These inputs are associated with individual serial channel data to the
SC68C2550B receive input circuits, A-B. The RX signal will be a logic 1 during reset, idle
(no data), or when the transmitter is disabled. During the local loop-back mode, the RX
input pin is disabled and TX data is connected to the UART RX input, internally.
Transmit data A, B. These outputs are associated with individual serial transmit channel
data from the SC68C2550B. The TX signal will be a logic 1 during reset, idle (no data), or
when the transmitter is disabled. During the local loop-back mode, the TX output pin is
disabled and TX data is internally connected to the UART RX input.
not connected
5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs
Rev. 02 — 28 April 2005
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
SC68C2550B
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