
PAN1326C Bluetooth Module
2 Overview
Product Specification Rev. 1.0
Page 18
2.6.2.7 Improved Algorithm For Lost Packets
The CC2564C features an improved algorithm for improving voice quality when received voice
data packets are lost. There are two options:
•
Repeat the last sample
– possible only for sample sizes up to 24 bits. For sample sizes >24
bits, the last byte is repeated.
•
Repeat a configurable sample of 8 to 24 bits (depends on the real sample size), in order to
simulate silence (or anything else) in the PCM bus. The configured sample will be written in
a specific register for each channel.
The choice between those two options is configurable separately for each channel.
2.6.2.8 Bluetooth/PCM Clock Mismatch Handling
In Bluetooth RX, the CC2564C receives RF voice packets and writes these to the codec I/F. If
the CC2564C receives data faster than the codec I/F output allows, an overflow will occur. In
this case, the Bluetooth has two possible behaviour m
odes: ‘allow overflow’ and ‘don’t allow
overflow’.
•
If overflow is allowed, the Bluetooth will continue receiving data and will overwrite any data
not yet sent to the codec.
•
If overflow is not allowed, RF voice packets received when buffer is full will be discarded.
2.6.2.9 Bluetooth Inter-IC Sound (I2S)
The CC2564C can be configured as an Inter-IC Sound (I2S) serial interface to an I2S codec
device. In this mode, the CC2564C audio codec interface is configured as a bi-directional, full-
duplex interface, with two time slots per frame: Time slot 0 is used for the left channel audio
data and time slot 1 for the right channel audio data. Each time slot is configurable up to 40
serial clock cycles in length and the frame is configurable up to 80 serial clock cycles in length.
Do not connect the microcontroller/DSP directly to the module’s PCM interface, a simple RC low
pass filter is recommended to improve noise suppression.