SC16C750B Philips Semiconductors, SC16C750B Datasheet - Page 24

• Manufacturer Part Number: SC16C750B
• Description: 5 V/ 3.3 V and 2.5 V UART with 64-byte FIFOs
• Manufacturer: Philips Semiconductors

Philips Semiconductors
9397 750 14453
Product data
7.6 Modem Control Register (MCR)
This register controls the interface with the modem or a peripheral device.
Table 18:
The flow control can be configured by programming MCR[1] and MCR[5] as shown in
Table
Table 19:
Bit
7
6
5
4
3
2
1
0
MCR[5] (AFE)
1
1
0
19.
Symbol
MCR[7]
MCR[6]
MCR[5]
MCR[4]
MCR[3]
MCR[2]
MCR[1]
MCR[0]
Modem Control Register bits description
Flow control configuration
Rev. 03 — 13 December 2004
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.
Loop-back. Enable the local loop-back mode (diagnostics). In this
mode the transmitter output (TX) and the receiver input (RX), CTS,
DSR, DCD, and RI are disconnected from the SC16C750B I/O pins.
Internally the modem data and control pins are connected into a
loop-back data configuration (see
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.
OUT2, INTx enable. Used to control the modem DCD signal in the
loop-back mode.
OUT1. This bit is used in the Loop-back mode only. In the loop-back
mode, this bit is used to write the state of the modem RI interface
signal via OUT1.
RTS
DTR
MCR[1] (RTS)
1
0
X
Logic 0 = Disable loop-back mode (normal default condition).
Logic 1 = Enable local loop-back mode (diagnostics).
Logic 0 = Forces INT output to the 3-State mode. In the loop-back
mode, sets OUT2 (DCD) internally to a logic 1.
Logic 1 = Forces the INT output to the active mode. In the
loop-back mode, sets OUT2 (DCD) internally to a logic 0.
Logic 0 = Force RTS output to a logic 1 (normal default condition).
Logic 1 = Force RTS output to a logic 0.
Logic 0 = Force DTR output to a logic 1 (normal default condition).
Logic 1 = Force DTR output to a logic 0.
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
Figure
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
6). In this mode, the receiver
SC16C750B
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