NuMicro® NUC029LEE/NUC029SEE
32-bit Arm
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Cortex
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-M0 Microcontroller
Aug, 2018
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between transmission and reception, and this delay feature must be implemented by software.
In IrDA mode, the DIV_X_EN (UA_BAUD [29]) register must be disabled.
Baud Rate = Clock / (16 * BRD)
, where BRD is Baud Rate Divider in UA_BAUD register.
The Figure 6.13-8 demonstrates the IrDA control block diagram.
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])
Figure 6.13-8 IrDA Control Block Diagram
IrDA SIR Transmit Encoder
The IrDA SIR Transmit Encoder modulates Non-Return-to Zero (NRZ) transmit bit stream output
from UART. The IrDA SIR physical layer specifies the use of Return-to-Zero, Inverted (RZI)
modulation scheme which represents logic 0 as an infra light pulse. The modulated output pulse
stream is transmitted to an external output driver and infrared light emitting diode.
In Normal mode, the transmitted pulse width is specified as 3/16 period of baud rate.
IrDA SIR Receive Decoder
The IrDA SIR Receive Decoder demodulates the Return-to-Zero bit stream from the input
detector and outputs the NRZ serial bits stream to the UART received data input. The decoder
input is normally high in idle state. (Because of this, IRCR (INV_RX [6]) should be set as 1 by
default).
A start bit is detected when the decoder input is LOW.
IrDA SIR Operation
The IrDA SIR encoder/decoder provides functionality which converts between UART data stream
and half-duplex serial SIR interface. The Figure 6.13-9 is IrDA encoder/decoder waveform.