MT9094 Ver la hoja de datos (PDF) - Mitel Networks
Número de pieza
componentes Descripción
Fabricante
MT9094 Datasheet PDF : 32 Pages
| |||
MT9094
logic low coincident with a falling edge of C4i. C4i
has a frequency (4096MHz) which is twice the data
rate. This clock is used to sample the data at the _
bit-cell position on DSTi and to make data available
on DSTo at the start of the bit-cell. C4i is also used
to clock the DPhone-II internal functions (i.e., DSP,
Filter/CODEC, HDLC) and to provide the channel
timing requirements.
The DPhone-II uses channels 1, 2 & 3 of the 32
channel frame. These channels are always defined,
beginning with the first channel after frame pulse, as
shown in Figure 6 (DSTi and DSTo channel
assignments). Channels are enabled independently
by the three control bits Ch1En -Ch3En residing in
the Timing Control Register (address15h).
Transmit PCM on DSTo
When high, PCM from the Filter/CODEC and DSP is
transmitted on DSTo in the selected ST-BUS
channel. When low, DSTo is forced to logic 0 for the
corresponding timeslot. If both Ch2EN and Ch3EN
are enabled, default is to channel 2.
Receive PCM from DSTi
When high, PCM from DSTi is routed to the DSP and
Filter/CODEC in the associated channel. If both
Ch2EN and Ch3EN are enabled the default is to
channel 2.
New Call Tone
Ch1EN - C-Channel
Channel 1 conveys the control/status
information for Mitel’s layer 1 transceiver. The
full 64kb/s bandwidth is available and is
assigned according to which transceiver is
being used. Consult the data sheet for the
selected transceiver for its bit definitions and
order of bit transfer. When this bit is high
register data is transmitted on DSTo. When
low, this timeslot is tri-stated on DSTo. Receive
C-Channel data (DSTi) is always routed to the
register regardless of this control bit's logic
state. C-channel data is transferred on the
ST-BUS MSB first by the DPhone-II.
Ch2EN and Ch3EN - B1-Channel and B2-Channel
Channels 2 and 3 are the B1 and B2 channels,
respectively. These bits (Ch2EN and Ch3EN)
are used to enable the PCM channels from/to
the DPhone-II as required.
The New Call Tone Generator produces a frequency
shifted square-wave used to toggle the speaker
driver outputs. This is intended for use where a
ringing signal is required concurrently with an
already established voice conversation in the
handset.
Programming of the DSP for New Call generator is
exactly as is done for the tone ringer micro-program
except that the OPT bit (DSP Control Register,
address 1Eh) is set high. In this mode the DSP does
not produce a frequency shifted squarewave output
to the filter CODEC section. Instead the DSP uses
the contents of the tone coefficient registers, along
with the tone warble rate register, to produce a gated
squarewave control signal output which toggles
between the programmed frequencies. This control
signal is routed to the New Call Tone block when the
NCT EN control bit is set (General Control Register,
address 0Fh). NCT EN also enables a separate gain
control block, for controlling the loudness of the
generated ringing signal. With the gain control block
set to 0dB the output is at maximum or 6 volts p-p.
Attenuation of the applied signal, in three steps of 8
dB, provide the four settings for New Call tone (0, -8,
-16, -24 dB). The NCT gain bits (NCTG0-NCTG1)
reside in the FCODEC Gain Control Register 2
(address 0Bh).
F0i
DSTi,
DSTo
125 µs
Not
Used
CHANNEL 1 CHANNEL 2 CHANNEL 3 CHANNELS 4 - 31
C-channel B1-channel B2-channel
Not Used
MSB first for C, B1 - & B2-
Channels
Figure 6 - ST-BUS Channel Assignment
7-55
Share Link: 