MT9126
Preliminary Information
EN1
MCLK
F0i
C2o
BCLK
PCMo1
PCMi1
VSS
LINEAR
ENB2/F0od
ENB1
PCMo2
PCMi2
SEL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
EN2
MS6
MS5
MS4
ADPCMo
ADPCMi
VDD
MS3
MS2
MS1
IC
PWRDN
FORMAT
A/µ
Figure 2 - Pin Connections
Pin Description
Pin #
1
Name
EN1
Description
Enable Strobe 1 (Output).
This 8 bit wide, active high strobe is active during the B1
PCM channel in ST-BUS mode. Becomes a single bit, high true pulse when LINEAR=1.
In SSI mode this output is high impedance.
Master Clock (input).
This is a 4.096 MHz (minimum) input clock utilized by the
transcoder function; it must be supplied in both ST-BUS and SSI modes of operation.
In ST-BUS mode the C4 ST-BUS clock is applied to this pin. This synchronous clock is
also used to control the data I/O flow on the PCM and ADPCM input/output pins
according to ST-BUS requirements.
In SSI mode this master clock input is derived from an external source and may be
asynchronous with respect to the 8 kHz frame. MCLK rates greater than 4.096 MHz are
acceptable in this mode since the data I/O rate is governed by BCLK.
3
4
F0i
C2o
Frame Pulse (Input).
Frame synchronization pulse input for ST-BUS operation. SSI
operation is enabled by connecting this pin to V
SS
.
2.048 MHz Clock (Output).
This ST-BUS mode bit clock output is the MCLK (C4) input
divided by two, inverted, and synchronized to F0i. This output is high-impedance during
SSI operation.
Bit Clock (Input).
128 kHz to 4096 kHz bit clock input for both PCM and ADPCM ports;
used in SSI mode only. The falling edge of this clock latches data into ADPCMi, PCMi1
and PCMi2. The rising edge clocks data out on ADPCMo, PCMo1 and PCMo2. This input
must be tied to V
SS
for ST-BUS operation.
Serial PCM Stream 1 (Output).
128 kbit/s to 4096 kbit/s serial companded/linear PCM
output stream. Data are clocked out by rising edge of BCLK in SSI mode. Clocked out by
MCLK divided by two in ST-BUS mode. See Figure 14.
Serial PCM Stream 1 (Input).
128 kbit/s to 4096 kbit/s serial companded/linear PCM
input stream. Data are clocked in on falling edge of BCLK in SSI mode. Clocked in at the
3/4 bit position of MCLK in ST-BUS mode. See Figure 14.
Digital Ground.
Nominally 0 volts.
Linear PCM Select (Input).
When tied to V
DD
the PCM I/O ports (PCM1,PCM2) are 16-
bit linear PCM. Linear PCM operates only at a bit rate of 2048 kbit/s. Companded PCM is
selected when this pin is tied to V
SS
. See Figures 5 & 8.
2
MCLK
5
BCLK
6
PCMo1
7
PCMi1
8
9
V
SS
LINEAR
8-34
MITEL [ MITEL NETWORKS CORPORATION ]
