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NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
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Revision V1.30
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Figure 5.16-7 UART CTSn Wake-Up Case 2
IrDA Mode
5.16.5.6
The UART Controller provides Serial IrDA (SIR, Serial Infrared) transmit encoder and receive decoder
function. The IrDA_EN(UART_FUN_SEL[2:0] = 010) bit are used to select IrDA function.
The SIR specification defines a short-range infrared asynchronous serial transmission mode with one
start bit, 8 data bits, and 1 stop bit. The maximum data rate is 115.2 Kbps (half duplex). The IrDA SIR
block contains an IrDA SIR Protocol encoder/decoder. The IrDA SIR protocol is half-duplex only. So it
cannot transmit and receive data at the same time. The IrDA SIR physical layer specifies a minimum
10 ms transfer delay between transmission and reception.
In IrDA Operation mode,
the receive FIFO trigger level must be “1” by setting RFITL(UA_FCR[7:4]) =
0000 and the DIV_X_EN(UA_BAUD[29]) bit must be disabled in IrDA mode operation (Mode 1).
Baud Rate = Clock / (16 * BRD ), where BRD is Baud Rate Divider in BRD(UA_BAUD[15:0]).
The following diagram demonstrates the IrDA control block diagram.
Figure 5.16-8 IrDA Block Diagram
sleep mode
CLK
CTSn
WAKE_
SYSTEM
INT_WAKE
UART
Controller
TX
RX
IrDA
SIR
IR_SOUT
IR_SIN
SOUT
SIN
IR
Transceiver
Emit Infra red ray
Detect Infra red ray
IRCR
BAUDOUT
IrDA_Enable
TX_SELECT
INV_TX
INV_RX
TX pin
RX pin
FUN_SEL=10b
(UA_FUN_SEL[1:0])