SC16IS740IPW PHILIPS [NXP Semiconductors], SC16IS740IPW Datasheet - Page 35

• Manufacturer Part Number: SC16IS740IPW
• Description: Single UART with I2C-bus/SPI interface, 64 bytes of transmit and receive FIFOs, IrDA SIR built-in support
• Manufacturer: PHILIPS [NXP Semiconductors]

NXP Semiconductors
9. RS-485 features
SC16IS740_750_760_5
Product data sheet
8.20 Extra Features Control Register (EFCR)
9.1 Auto RS-485 RTS control
Table 31.
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Normally the RTS pin is controlled by MCR bit 1, or if hardware flow control is enabled, the
logic state of the RTS pin is controlled by the hardware flow control circuitry. EFCR
register bit 4 will take the precedence over the other two modes; once this bit is set, the
transmitter will control the state of the RTS pin. The transmitter automatically asserts the
RTS pin (logic 0) once the host writes data to the transmit FIFO, and deasserts RTS pin
(logic 1) once the last bit of the data has been transmitted.
To use the auto RS-485 RTS mode the software would have to disable the hardware flow
control function.
Bit
7
6
5
4
3
2
1
0
For SC16IS760 only.
Symbol
IRDA MODE
-
RTSINVER
RTSCON
-
TXDISABLE
RXDISABLE
9-BIT MODE
Extra Features Control Register bits description
Rev. 05 — 16 November 2006
Single UART with I
Description
IrDA mode
reserved
invert RTS signal in RS-485 mode
enable the transmitter to control the RTS pin
reserved
Disable transmitter. UART does not send serial data out on the
transmit pin, but the transmit FIFO will continue to receive data from
host until full. Any data in the TSR will be sent out before the
transmitter goes into disable state.
Disable receiver. UART will stop receiving data immediately once this
bit set to a 1, and any data in the TSR will be sent to the receive FIFO.
User is advised not to set this bit during receiving.
Enable 9-bit or Multidrop mode (RS-485).
0 = IrDA SIR,
1 = IrDA SIR,
0: RTS = 0 during transmission and RTS = 1 during reception
1: RTS = 1 during transmission and RTS = 0 during reception
0 = transmitter does not control RTS pin
1 = transmitter controls RTS pin
0: transmitter is enabled
1: transmitter is disabled
0: receiver is enabled
1: receiver is disabled
0: normal RS-232 mode
1: enables RS-485 mode
3
1
16
4
2
C-bus/SPI interface, 64-byte FIFOs, IrDA SIR
pulse ratio, data rate up to 1.152 Mbit/s
pulse ratio, data rate up to 115.2 kbit/s
SC16IS740/750/760
© NXP B.V. 2006. All rights reserved.
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