The ML7204-001 is a speech codec specifically developed as
an analog front end of communication devices supporting VoIP
(Voice over Internet Protocol). It performs compression and
decompression in G.711 format with high sound quality and in
G.729.A format with a high compression rate. Equipped with the
PLC (Packet Loss Concealment) function, it will further improve
voice quality. In addition to a two-channel analog interface,
the ML7204-001 supports DMA transfer and frame transfer of
parallel bus system as well as data transfer of serial bus system
as the interfaces with the processor, allowing easy expansion to
support multi-channels.
Also incorporated is an echo canceller with a maximum of 32
ms delay; it cannot only cancel line echoes when an SLIC is
connected but also cancel acoustic echoes when the system
supports hand-free speech. Furthermore, the ML7204-001
is equipped with an FSK signal generator and a detector for
implementing the number display function. Additional functions
include a tone detector that can detect CED tone during fax
communications is provided, helping to disable the echo
canceller during mute connections. Last but not least, the
ML7204-001 contains a DTMF tone detector, a number of tone
generators and a three-way speech function. This is an optimum
LSI to add VoIP capabilities to TA’s, routers, IP telephony and
phones.
The ML7204 evaluation board is available to facilitate the
evaluation of the ML7204 voice CODEC for VoIP. It is equipped
with a 2-channel microphone amplifier and speaker amplifier to
allow connection of a handset and headset as voice I/O devices.
By connecting to a controller via a 50-pin connector, the ML7204
Evaluation Board facilitates the control of the ML7204. |
