IRCC SMSC Corporation, IRCC Datasheet - Page 33

• Manufacturer Part Number: IRCC
• Description: INFRARED COMMUNICATIONS CONTROLLER
• Manufacturer: SMSC Corporation

Half Duplex, bit 2
When Half Duplex is zero (default), the 16550A
is in full duplex mode. The Half Duplex bit only
supports the 16550A UART; i.e., this bit has no
effect on the IrCC SCE. The Half Duplex bit is
analogous to the chip-level configuration register
Half Duplex bit and has the same affect on the
UART. Provisions must be made in legacy
devices to accommodate Half Duplex selection
through
registers or the IrCC Half Duplex bit; i.e., the last
write from either source determines the current
mode selection and is visible in both registers.
Tx/Rx Polarity Bits, 0 - 1
The Tx and Rx Polarity bits define the active
states for signals entering and exiting the Output
Multiplexer ports. IrCC Active states are typically
decoded as zero. The Tx Polarity bit default is
one; the Rx Polarity bit default is zero.
either
D6
0
0
0
0
0
0
0
0
1
D5
0
0
0
0
1
1
1
1
X
the
D4
chip-level
X
0
0
1
1
0
0
1
1
SIGNAL
0
0
1
1
D3
0
1
0
1
0
1
0
1
X
Table 20 - Tx/Rx Polarity Bit Effects
configuration
POLARITY BIT
COM
IrDA SIR - A
ASK IR
IrDA SIR - B
IrDA HDLC
IrDA4PPM
CONSUMER
RAW IR
OTHER
MODE
0
1
0
1
33
Up to 115.2Kbps, Variable 3/16 Pulse
Up to 115.2Kbps, Fixed 1.6us Pulse
Includes 4Mbps
16550 UART COM Port (default)
Amplitude Shift Keyed Ir Interface
Includes.576Mbps & 1.152Mbps
TV Remote
Direct IR Diode Control
Reserved
For backward compatibility, the Tx and Rx
Polarity bits do not apply to COM mode; i.e.,
when the Block Control bits are zero.
relationship between the Output Multiplexer port
signals and the Polarity bits is an exclusive-or
(Table 20). For example, if the IRRx pin in the
Output Multiplexer is one and the Rx Polarity bit
is zero, the signal is inactive and therefore
decoded as a one. The IrCC Tx Polarity bit (bit
1) is equivalent to the Transmit Polarity bit in the
chip-level configuration space of earlier devices;
e.g., the FDC37C93X IR Option Register, Serial
Port 2, Logical Device 5, Register 0xF1. The Rx
Polarity bit (bit 0) is equivalent to the Receive
Polarity bit in the same register. Provisions have
been made in legacy devices to accommodate
Polarity bit selection through either the chip-level
configuration registers or the SCE registers; i.e.,
the last write from either source determines the
current Polarity bit value and is visible in both
registers.
DECODED SIGNAL
DESCRIPTION
0
1
1
0
The