MT90823 Zarlink Semiconductor, MT90823 Datasheet - Page 7

• Manufacturer Part Number: MT90823
• Description: 3V Large Digital Switch
• Manufacturer: Zarlink Semiconductor

Data Sheet
Device Overview
The MT90823 Large Digital Switch is capable of switching up to 2,048 × 2,048 channels. The MT90823 is designed
to switch 64 kb/s PCM or N x 64 kb/s data. The device maintains frame integrity in data applications and minimum
throughput delay for voice applications on a per channel basis.
The serial input streams of the MT90823 can have a bit rate of 2.048, 4.096 or 8.192 Mbit/s and are arranged in
125µs wide frames, which contain 32, 64 or 128 channels, respectively. The data rates on input and output streams
are identical.
By using Mitel’s message mode capability, the microprocessor can access input and output time-slots on a per
channel basis. This feature is useful for transferring control and status information for external circuits or other ST-
BUS devices. The MT90823 automatically identifies the polarity of the frame synchronization input signal and
configures its serial streams to be compatible to either ST-BUS or GCI formats.
Two different microprocessor bus interfaces can be selected through the Input Mode pin (IM): Non-multiplexed or
Multiplexed. These interfaces provide compatibility with multiplexed and Motorola multiplexed/non-multiplexed
buses.
The frame offset calibration function allows users to measure the frame offset delay using a frame evaluation pin
(FE). The input offset delay can be programmed for individual streams using internal frame input offset registers,
see Table 11.
The internal loopback allows the ST-BUS output data to be looped around to the ST-BUS inputs for diagnostic
purposes.
Pin Description (continued)
PLCC
77 -
84
76
84
-
MQFP
58-65
1 - 4,
100
27 -
51 -
77 -
30,
57
54
80
LQFP
1 - 2,
55 -
24 -
49 -
74 -
99 -
100
100
27,
52,
77,
Pin #
54
62
A11,B10,A10,B9,
A9,A8,B8,A7
BGA
120
B11
STo0 - 7
Zarlink Semiconductor Inc.
Name
ODE
NC
Output Drive Enable (5V Tolerant Input): This is the
output enable control for the STo0-15 serial outputs.
When ODE input is low and the OSB bit of the IMS
register is low, STo0-15 are in a high impedance state.
If this input is high, the STo0-15 output drivers are
enabled. However, each channel may still be put into a
high impedance state by using the per channel control
bit in the connection memory.
Data Stream Output 0 to 7 (5V Tolerant Three-state
Outputs): Serial data Output stream. These streams
have selectable data rates of 2.048, 4.096 or 8.192
Mb/s.
No connection.
Description
MT90823
7