User's Manual

Bluegiga Technologies Oy
Page 26 of 52
14 Audio Interfaces
BT111 has digital audio interface that is configurable as either a PCM or I
2
S port.
14.1 PCM Interface
The audio PCM interface on the BT111 supports:
 Continuous transmission and reception of PCM encoded audio data over Bluetooth.
 Processor overhead reduction through hardware support for continual transmission and reception of
PCM data.
 A bidirectional digital audio interface that routes directly into the baseband layer of the firmware. It
does not pass through the HCI protocol layer.
 Hardware on BT111 for sending data to and from a SCO connection.
 Up to 3 SCO connections on the PCM interface at any one time.
 PCM interface master, generating PCM_SYNC and PCM_CLK.
 PCM interface slave, accepting externally generated PCM_SYNC and PCM_CLK.
 Various clock formats including:
o Long Frame Sync
o Short Frame Sync
o GCI timing environments
 13-bit or 16-bit linear, 8-bit μ-law or A-law companded sample formats.
 Receives and transmits on any selection of 3 of the first 4 slots following PCM_SYNC.
The PCM configuration options are enabled by setting PSKEY_PCM_CONFIG32.
14.1.1 PCM Interface Master/Slave
When configured as the master of the PCM interface, BT111 generates PCM_CLK and PCM_SYNC.
PCM_OUT
PCM_IN
PCM_CLK
PCM_SYNC
128/256/512/1536/2400kHz
8/48kHz
Figure 15: BT111 as PCM master