IRCC SMSC Corporation, IRCC Datasheet - Page 13

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

Receiver Bit Cell Synchronization
The
incoming ASK waveforms into NRZ data for the
SCE.
demodulated incoming infrared data to indicate
changes in bit state.
For continuous periods of high or low data
without transitions, the IrCC samples the signal
level in the center of each incoming bit period.
Using the Receiver Bit Cell Synchronization
mechanism, any transition resets the timer that is
used in the sampling process to eliminate errors
due to timing differences between the receive
decoder and the incoming bit period (Figure 6).
Consumer
The IrCC uses the edges of the
IR
NRZ Rx Data
NRZ Rx Data
(No SYNC)
FIGURE 6 - TV REMOTE RECEIVER: SYNC VS. NO SYNC
IR Rx Data
IR Rx Data
Receiver
(SYNC)
Clock
Clock
demodulates
1
1
1
1
Sync
2
2
1
1
3
3
0
0
13
4
4
0
Receiver synchronization can be disabled to
allow direct sampling of the demodulated
incoming infrared data stream at some preset
receive bit rate. This is useful in situations where
the speed of the receive data is not strictly
known. In such cases, the receive bit rate is set
as high as possible, the
Synchronization is disabled, and the system
software is used to measure the bit-cell period
from the oversampled data.
parameters can then be used to switch to the
synchronized, fixed bit-cell mode to reduce
processing overhead in the host CPU for all
future transactions.
0
5
5
0
0
6
6
1
1
7
7
1
1
Sync
8
8
1
1
9
1
9
10
0
10
0
11
Receiver Bit Cell
The learned