Bluetooth Audio Module
PCM Interface
PCM_OUT
SPDIF Interface
SPDIF_OUT
I²S Interface
SD_OUT
PCM_IN
SPDIF_IN
SD_IN
WS
PCM_SYNC
PCM_CLK
-
-
SCK
Table 11: Alternative Functions of the Digital Audio Bus Interface on the PCM Interface
The audio input circuitry consists of a dual audio input that can be configured to be either
single-ended or fully differential and programmed for either microphone or line input. It has an
analogue and digital programmable gain stage for optimization of different microphones.
The audio output circuitry consists of a dual differential class A-B output stage.
6.7.1 PCM
The audio pulse code modulation (PCM) interface supports continuous transmission and
reception of PCM encoded audio data over Bluetooth.
Hardware on EH-MB05 allows the data to be sent to and received from a SCO connection. Up
to three SCO connections can be supported by the PCM interface at any one time.
EH-MB05 can operate as the PCM interface master generating PCM_SYNC and PCM_CLK or
as a PCM interface slave accepting externally generated PCM_SYNC and PCM_CLK.
EH-MB05 is compatible with a variety of clock formats, including Long Frame Sync, Short
Frame Sync and GCI timing environments.
It supports 13-bit or 16-bit linear, 8-bit u-law or A-law companded sample formats and can
receive and transmit on any selection of three of the first four slots following PCM_SYNC.
EH-MB05 interfaces directly to PCM audio devices including the following:
■ Qualcomm MSM 3000 series and MSM 5000 series CDMA baseband devices
■ OKI MSM7705 four channel A-law and μ-law CODEC
■ Motorola MC145481 8-bit A-law and μ-law CODEC
■ Motorola MC145483 13-bit linear CODEC
■ STW 5093 and 5094 14-bit linear CODECs(8)
■ EH-MB05 is also compatible with the Motorola SSI interface
6.7.2 Digital Audio Interface (I
2
S)
The digital audio interface supports the industry standard formats for I2S, left-justified or right-
justified. The interface shares the same pins of the PCM interface as Table 11.
The I2S interface can be enabled by using AT+ commands. The module is an I2S slave device
with the default firmware. Contact with EHong for special firmware when use the module as an
I2S master. The I2S support following formats:
Shanghai Ehong Technologies Inc
