sc16c751b NXP Semiconductors, sc16c751b Datasheet - Page 18

• Manufacturer Part Number: sc16c751b
• Description: 5 V, 3.3 V And 2.5 V Uart With 64-byte Fifos
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SC16C751B_2
Product data sheet
7.6 Modem Control Register (MCR)
This register controls the interface with the modem or a peripheral device.
Table 16.
The flow control can be configured by programming MCR[1] and MCR[5] as shown in
Table
Table 17.
Bit
7
6
5
4
3:2
1
0
MCR[5] (AFE)
1
1
0
17.
Symbol
MCR[7]
MCR[6]
MCR[5]
MCR[4]
MCR[3:2]
MCR[1]
MCR[0]
Modem Control Register bits description
Flow control configuration
Description
reserved; set to 0
reserved; set to 0
AFE. This bit is the auto flow control enable. When this bit is set, the auto
flow control is enabled.
Loopback. Enable the local Loopback mode (diagnostics). In this mode the
transmitter output (TX) and the receiver input (RX), CTS are disconnected
from the SC16C751B I/O pins. Internally the modem data and control pins
are connected into a loopback data configuration (see
mode, the receiver and transmitter interrupts remain fully operational. The
Modem Control Interrupts are also operational, but the interrupts’ sources
are switched to the lower four bits of the Modem Control. Interrupts continue
to be controlled by the IER register.
reserved
RTS
reserved
Rev. 02 — 10 October 2008
logic 0 = disable Loopback mode (normal default condition)
logic 1 = enable local Loopback mode (diagnostics)
logic 0 = force RTS output to a logic 1 (normal default condition)
logic 1 = force RTS output to a logic 0
MCR[1] (RTS)
1
0
X
5 V, 3.3 V and 2.5 V UART with 64-byte FIFOs
Flow configuration
auto RTS and CTS enabled
auto CTS only enabled
auto RTS and CTS disabled
SC16C751B
Figure
© NXP B.V. 2008. All rights reserved.
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