The audio PCM interface on the CSR8640 BGA 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 the CSR8640 BGA 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:
■
Long Frame Sync
■
Short Frame Sync
■
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 the PSKEY_PCM_CONFIG32.
9.3.1
PCM Interface Master/Slave
When configured as the master of the PCM interface, CSR8640 BGA generates PCM_CLK and PCM_SYNC.
G-
T
W
-00
00217.3.4
128/256/512/1536/2400kHz
8/48kHz
PCM_OUT
PCM_IN
PCM_CLK
PCM_SYNC
Figure 9.9: PCM Interface Master
G-
T
W
-000
0218.3.3
Up to 2400kHz
8/48kHz
PCM_OUT
PCM_IN
PCM_CLK
PCM_SYNC
Figure 9.10: PCM Interface Slave
Advance Information
This material is subject to CSR's non-disclosure agreement
© Cambridge Silicon Radio Limited 2011
Page 48 of 110
CS-209182-DSP1
CSR8640 BGA
Data Sheet
