
Advanced Notebook I/O for ISA or LPC Designs
Datasheet
SMSC SIO10N268
Page 109
Rev. 0.5 (03-24-05)
DATASHEET
v1.2 (SIR/FIR), ASKIR, and Consumer IR (Figure 8.8). For more information, consult the SMSC Infrared
Communication Controller (IRCC) specification.
The IrDA v1.0 (SIR) and ASKIR formats are driven by the ACE registers found in UART2. The UART2
registers are described in “Serial Port (UART)” section. The base address for UART2 is programmed in
CR25, the UART2 Base Address Register (see section CR25 subsection in the Configuration seciton).
The IrDA V1.2 (FIR) and Consumer IR formats are driven by the SCE registers. Descriptions of these
registers can be found in the SMSC Infrared Communications Controller Specification. The Base Address
for the SCE registers is programmed in CR2B, the SCE Base Address Register (see CR28 subsection in
the Configuration section).
8.9.1
IrDA SIR/FIR and ASKIR
IrDA SIR (v1.0) specifies asynchronous serial communication at baud rates up to 115.2Kbps. Each byte is
sent serially LSB first beginning with a zero value start bit. A zero is signaled by sending a single infrared
pulse at the beginning of the serial bit time. A one is signaled by the absence of an infrared pulse during
the bit time. Please refer to “Timing Diagrams” section for the parameters of these pulses and the IrDA
waveforms.
IrDA FIR (v1.2) includes IrDA v1.0 SIR and additionally specifies synchronous serial communications at
data rates up to 4Mbps.
Data is transferred LSB first in packets that can be up to 2048 bits in length. IrDA v1.2 includes .576Mbps
and 1.152Mbps data rates using an encoding scheme that is similar to SIR. The 4Mbps data rate uses a
pulse position modulation (PPM) technique.
The ASKIR infrared allows asynchronous serial communication at baud rates up to 19.2Kbps. Each byte is
sent serially LSB first beginning with a zero value start bit. A zero is signaled by sending a 500KHz carrier
waveform for the duration of the serial bit time. A one is signaled by the absence of carrier during the bit
time. Refer to “Timing Diagrams” section for the parameters of the ASKIR waveforms.
8.9.2
Consumer IR
The SIO10N268 Consumer IR interface is a general-purpose Amplitude Shift Keyed encoder/decoder with
programmable carrier and bit-cell rates that can emulate many popular TV Remote encoding formats;
including, 38KHz
PPM, PWM and RC-5.
The carrier frequency is programmable from 1.6MHz to
6.25KHz. The bit-cell rate range is 100KHz to 390Hz.
8.9.3
Hardware Interface
The SIO10N268 IR hardware interface is shown in Figure 8.8. This interface supports two types of
external FIR transceiver modules. One uses a mode pin (IR Mode) to program the data rate, while the
other has a second Rx data pin (IRRX3). The SIO10N268 uses Pin 63 for these functions. Pin 62 has IR
Mode and IRRX3 as its first and second alternate function, respectively. These functions are selected
through CR29 as shown in Table 8.38.