sc16c852viet NXP Semiconductors, sc16c852viet Datasheet - Page 36

• Manufacturer Part Number: sc16c852viet
• Description: Sc16c852v 1.8 V Dual Uart, 5 Mbit/s Max. With 128-byte Fifos, Infrared Irda , And Xscale Vlio Bus Interface
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SC16C852V_4
Product data sheet
7.20 RS-485 turn-around time delay (RS485TIME)
7.21 Advanced Feature Control Register 1 (AFCR1)
The value in this register controls the turn-around time of the external line transceiver in
bit time. In automatic 9-bit mode, the 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 the RTSA/RTSB or DTRA/DTRB pin (logic 0) to turn
the external RS-485 transceiver around for receiving.
Table 32.
Table 33.
[1]
Bit
7:0
Bit
7
6:5
4
3
2
1
0
It takes 4 XTAL1 clocks to reset the device.
Symbol
RS485TIME[7:0] External RS-485 transceiver turn-around time delay. The value
Symbol
AFCR1[7]
AFCR1[6:5]
AFCR1[4]
AFCR1[3]
AFCR1[2]
AFCR1[1]
AFCR1[0]
RS-485 programmable turn-around time register
Advanced Feature Control Register 1 bits description
Dual UART with 128-byte FIFOs, IrDA, and XScale VLIO bus interface
Description
Concurrent write. When this bit is set the host can write concurrently to the
same register of all channels.
reserved
Sleep RXlow. Program RX input to be edge-sensitive or level-sensitive.
reserved
RTS/CTS mapped to DTR/DSR. Switch the function of RTS/CTS to
DTR/DSR.
SReset. Software reset. A write to this bit will reset the UART. Once the
UART is reset this bit is automatically set to 0.
TSR interrupt. Select TSR interrupt mode.
Rev. 04 — 14 January 2008
0 = normal operation
1 = concurrent write operation
0 = RX input is level sensitive. If RXA/RXB pin is LOW, the UART will not
go to sleep. Once the UART is in Sleep mode, it will wake up if RXA/RXB
pin goes LOW.
1 = RX input is edge sensitive. UART will go to sleep even if RXA/RXB
pin is LOW, and will wake up when RXA/RXB pin toggles.
0 = RTS and CTS signals are used for hardware flow control
1 = DTR and DSR signals are used for hardware flow control. RTS and
CTS retain their functionality.
0 = transmit empty interrupt occurs when transmit FIFO falls below the
trigger level or becomes empty.
1 = transmit empty interrupt occurs when transmit FIFO fall below the
trigger level, or becomes empty and the last stop bit has been shift out
the transmit shift register.
Description
represents the bit time at the programmed baud rate.
[1]
SC16C852V
© NXP B.V. 2008. All rights reserved.
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