Allwinner A20 - Page 628

A20 User Manual (Revision 1.2) Copyright © 2013 Allwinner Technology Co., Ltd. All Rights Reserved. Page 628 / 812
Port Name
Width
Direction
Description
has detected a carrier
UART1_RING
IN
UART Ring Indicator
This active low signal is an input showing when Modem
has sensed a ring signal on the telephone line
UART2_TX
1
OUT
UART Serial Bit output
UART2_RX
1
IN
UART Serial Bit input
UART2_RTS
1
OUT
UART Request To Send
This active low output signal informs Modem that the
UART is ready to send data
UART2_CTS
1
IN
UART Clear To End
This active low signal is an input showing when Modem is
ready to accept data
UART3_TX
1
OUT
UART Serial Bit output
UART3_RX
1
IN
UART Serial Bit input
UART3_RTS
1
OUT
UART Request To Send
This active low output signal informs Modem that the
UART is ready to send data
UART3_CTS
1
IN
UART Clear To End
This active low signal is an input showing when Modem is
ready to accept data
UART4_TX
1
OUT
UART Serial Bit output
UART4_RX
1
IN
UART Serial Bit input
UART5_TX
1
OUT
UART Serial Bit output
UART5_RX
1
IN
UART Serial Bit input
UART6_TX
1
OUT
UART Serial Bit output
UART6_RX
1
IN
UART Serial Bit input
UART7_TX
1
OUT
UART Serial Bit output
UART7_RX
1
IN
UART Serial Bit input
IRDA INVERTED SIGNALS
When the UART is working in IrDA mode (MCR[6]=’1’), if HALT[4] is set to ‘1’, the signal is inverted
before transferring to pin SOUT and if HALT[5] is set to ‘1’, the signal is inverted after receiving from
pin SIN