Data Formatting; Wideband Speech Support - Laird BT85 Series User Manual

Bluetooth v4.2 dual-mode usb hci module
Table of Contents

Advertisement

BT85x Series
Datasheet
Figure 5
and
Table 12
shows PCM Timing Diagram and Specifications for the slave mode of long-frame.
Figure 5: PCM timing diagram (Long-Frame Sync, Slave Mode)
Table 12: PCM Interface timing specifications (Long-Frame Sync, Slave Mode)
Ref No.
1
PCM bit clock frequency
2
3
4
5
6
7
8
Delay from rising edge of PCM_BCLK during last bit
9
period to PCM_OUT becoming high impedance

8.3.3. Data Formatting

The BT85-Sx0 may be configured to generate and accept several different data formats. For conventional
narrowband speech mode, the BT850 uses 13 of the 16 bits in each PCM frame. The location and order of these
13 bits can be configured to support various data formats on the PCM interface. The remaining three bits are
ignored on the input and may be filled with 0s, 1s, a sign bit, or a programmed value on the output. The default
format is 13-bit 2's complement data, left justified, and clocked MSB first.

8.3.4. Wideband Speech Support

When the host encodes Wideband Speech (WBS) packets in transparent mode, the encoded packets are
transferred over the PCM bus for an eSCO voice connection. In this mode, the PCM bus is typically configured in
master mode for a 4-kHz sync rate with 16-bit samples, resulting in a 64 Kbps bit rate. The BT850-Sx also
supports slave transparent mode using a proprietary rate-matching scheme. In SBC-code mode, linear 16-bit
data at 16 kHz (256 Kbps rate) is transferred over the PCM bus.
Embedded Wireless Solutions Support Center:
http://ews-support.lairdtech.com
www.lairdtech.com/bluetooth
Characteristics
PCM bit clock LOW
PCM bit clock HIGH
PCM_SYNC setup
PCM_SYNC_hold
PCM_OUT delay
PCM_IN setup
PCM_IN hold
© Copyright 2017 Laird. All Rights Reserved
Minimum
Typical
-
41
41
8
8
0
8
8
0
13
Maximum
Unit
-
12
MHz
-
-
ns
-
-
ns
-
-
ns
-
-
ns
-
25
ns
-
-
ns
-
-
ns
-
25
ns
Americas: +1-800-492-2320
Europe: +44-1628-858-940
Hong Kong: +852 2923 0610

Advertisement

Table of Contents
loading

This manual is also suitable for:

Bt850-stBt850-sa

Table of Contents