LPC47N227TQFP Standard Microsystems (SMSC), LPC47N227TQFP Datasheet - Page 86

• Manufacturer Part Number: LPC47N227TQFP
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LPC47N227TQFP

• Lead Free Status / RoHS Status: Not Compliant

If the Half Duplex option is chosen there is an IR Half Duplex Time-out that constrains IRCC direction
mode changes. This time-out starts as each bit is transferred and prevents direction mode changes
until the time-out expires. The timer is restarted whenever new data arrives in the current direction
mode. For example, if data is loaded into the transmit buffer while a character is being received, the
transmission will not start until the last bit has been received and the time-out expires. If the start bit of
another character is received during this time-out, the timer is restarted after the new character is
received. The Half Duplex Time-out is programmable from 0 to 25.5ms in 100#s increments (see
section (See subsection CR2D in the Configuration section).
IR Transmit Pins
The TXD2 and IRTX2 pins default to output, low on VCC POR and hard reset. These pins are not
powered by VTR. These pins function as described below.
Following a VCC POR, the TXD2 and IRTX2 pins will be output and low. They will remain low until one
of the following conditions are met.
IRTX2 Pin (CR0A bits [7:6]=01):
!"
This pin will remain low following a VCC POR until serial port 2 is enabled by setting the UART2
power down bit (CR02, bit 7), at which time the pin will reflect the state of the IR transmit output of
the IRCC block (if IR is enabled through the IR Option Register for Serial Port 2).
RAW
COM
IrDA
ASK
FIR
TV
IrCC Block
MUX
OUT
FIGURE 2 – INFRARED INTERFACE BLOCK DIAGRAM
G.P. Data
Fast Bit
COM
AUX
IR
TX1
RX1
TX2
RX2
TX3
RX3
IR MODE
FAST
HPMODE
86
1
2
0
1
1
0
IR Mode
/IRRX3
TXD2
RXD2
IRTX2
IRRX2