IRCC2.0 SMSC Corporation, IRCC2.0 Datasheet - Page 14

• Manufacturer Part Number: IRCC2.0
• Description: Infrared Communications Controller
• Manufacturer: SMSC Corporation

IrDA SIR AND SHARP ASK IR INTERFACE
This interface uses the ACE UART to provide a
two-way wireless communications port using
infrared as a transmission medium. Two distinct
implementations have been provided in this block
of the IrCC 2.0, IrDA SIR and Sharp ASK IR.
IrDA SIR allows serial communication at baud
rates up to 115k Baud.
serially beginning with a zero value start bit.
Sending a single infrared pulse at the beginning
of the serial bit time signals a zero. Sending no
infrared pulse during the bit time signals a one.
Please refer to Figure 7 through Figure 10 for the
parameters of these pulses and the IrDA
waveform.
The SHARP ASK interface allows asynchronous
amplitude shift keyed serial communication at
baud rates up to 19.2k Baud. Each word is sent
serially beginning with a zero value start bit.
Sending a 500kHz waveform for the duration of
the serial bit time signals a zero.
NRZ Rx Data
NRZ Rx Data
FIGURE 6 - REMOTE CONTROL RECEIVER: SYNC VS. NO SYNC
(No SYNC)
IR Rx Data
IR Rx Data
(SYNC)
Clock
Clock
Each word is sent
1
1
1
1
Sync
2
2
1
1
3
3
0
0
4
14
4
0
0
Sending no transmission during the bit time
signals a one. Please refer to the AC timing for
the parameters of the ASKIR waveform.
If the Half Duplex option is chosen, there is a
time-out when the direction of the transmission is
changed.
transferred during a transmission and blocks the
receiver input until the time-out expires. If the
transmit buffer is loaded with more data before
the time-out expires, the timer is restarted after
the new byte is transmitted. If data is loaded into
the transmit buffer while a character is being
received, the transmission will not start until the
time-out expires after the last receive bit has
been received.
character is received during this time-out, the
timer is restarted after the new character is
received. The time-out is programmable up to a
maximum of 10ms through the IR Half-Duplex
Time-Out Configuration Register.
5
5
0
0
6
6
1
1
7
This time-out starts at the last bit
7
1
1
Sync
8
8
If the start bit of another
1
1
9
1
9
10
0
10
0
11