sc16c652 NXP Semiconductors, sc16c652 Datasheet - Page 22

• Manufacturer Part Number: sc16c652
• Description: Dual Uart With 32 Bytes Of Transmit And Receive Fifos
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 11634
Product data
7.6 Modem Control Register (MCR)
This register controls the interface with the modem or a peripheral device.
Table 20:
Bit
7
6
5
4
3
2
1
0
Symbol
MCR[7]
MCR[6]
MCR[5]
MCR[4]
MCR[3]
MCR[2]
MCR[1]
MCR[0]
Modem Control Register bits description
Rev. 04 — 20 June 2003
Description
Clock select
Reserved; set to ‘0’.
Reserved; set to ‘0’.
Loop-back. Enable the local loop-back mode (diagnostics). In this
mode the transmitter output (TX) and the receiver input (RX), CTS,
DSR, CD, and RI are disconnected from the SC16C652 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.
OP2/INT enable
(OP1). OP1A/OP1B are not available as an external signal in the
SC16C652. This bit is instead 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.
RTS
DTR
Logic 0 = Divide by 1 clock input.
Logic 1 = Divide by 4 clock input.
Logic 0 = Disable loop-back mode (normal default condition).
Logic 1 = Enable local loop-back mode (diagnostics).
Logic 0 = Forces INT (A-B) outputs to the 3-State mode and sets
OP2 to a logic 1 (normal default condition).
Logic 1 = Forces the INT (A-B outputs to the active mode and sets
OP2 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.
Dual UART with 32 bytes of transmit and receive FIFOs
Figure
© Koninklijke Philips Electronics N.V. 2003. All rights reserved.
4). In this mode, the receiver
SC16C652
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