sc16c852 NXP Semiconductors, sc16c852 Datasheet - Page 38

• Manufacturer Part Number: sc16c852
• Description: 2.5 V To 3.3 V Dual Uart, 5 Mbit/s Max. With 128-byte Fifos, Infrared Irda And 16 Mode Or 68 Mode Bus Interface
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SC16C852_1
Product data sheet
7.20 RS-485 turn-around time delay (RS485TIME)
7.21 Advanced Feature Control Register 2 (AFCR2)
The value in this register controls the turn-around time of the external line transceiver in
bit time. In automatic 9-bit mode RTSA/RTSB or DTRA/DTRB pin is used to control the
direction of the line driver, after the last bit of data has been shifted out of the transmit shift
register the UART will count down the value in this register. When the count value reaches
zero, the UART will assert RTSA/RTSB or DTRA/DTRB pin (logic 0) to turn the external
RS-485 transceiver around for receiving.
Table 32.
Table 33.
Bit
7:0
Bit
7:6
5
4
3
2
1
0
Symbol
RS485TIME[7:0]
Symbol
AFCR2[7:6]
AFCR2[5]
AFCR2[4]
AFCR2[3]
AFCR2[2]
AFCR2[1]
AFCR2[0]
RS-485 programmable turn-around time register bits description
Advanced Feature Control Register 2 register bits description
Rev. 01 — 31 August 2009
Description
reserved
RTSInvert. Invert RTS or DTR signal in automatic 9-bit mode.
logic
RTSCon. Enable the transmitter to control RTSx or DTRx pin in
automatic 9-bit mode.
logic
RS485 RTS/DTR. Select RTSx or DTRx pin to control the external
transceiver.
logic
TXDisable. Disable transmitter
RXDisable. Disable receiver
9-bitMode. Enable 9-bit mode or Multidrop (RS-485) mode
logic
Dual UART with 128-byte FIFOs and IrDA encoder/decoder
logic 0 = RTS or DTR is set to 0 by the UART during transmission,
and to 1 during reception
logic 1 = RTS or DTR is set to 1 by the UART during transmission,
and to 0 during reception
logic 0 = transmitter does not control RTSx or DTRx pin
logic 1 = transmitter controls RTSx or DTRx pin
logic 0 = RTSx pin is used to control the external transceiver
logic 1 = DTRx pin is used to control the external transceiver
logic 0 = transmitter is enabled
logic 1 = transmitter is disable
logic 0 = receiver is enabled
logic 1 = receiver is disable
logic 0 = normal RS-232 mode
logic 1 = enable 9-bit mode
Description
External RS-485 transceiver turn-around time delay. The value
represents the bit time at the programmed baud rate.
SC16C852
© NXP B.V. 2009. All rights reserved.
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