Features: • 12,288-channel x 12,288-channel non-blocking
unidirectional switching.The Backplane and
Local inputs and outputs can be combined to
form a non-blocking switching matrix with 48
stream inputs and 48 stream outputs.
• 8,192-channel x 4,096-channel blocking
Backplane to Local stream switch.
• 4,096-channel x 8,192-channel non-blocking
Local to Backplane stream switch.
• 8,192-channel x 8,192-channel non-blocking
Backplane input to Backplane output switch.
• 4,096-channel x 4,096-channel non-blocking
Local input to Local output stream switch.
• Rate conversion on all data paths, Backplane to
Local, Local to Backplane, Backplane to
Backplane and Local to Local streams.
• Backplane port accepts 32 ST-BUS streams with
data rates of 2.048Mb/s, 4.096Mb/s, 8.192Mb/s
or 16.384Mb/s in any combination, or a fixed
allocation of 16 streams at 32.768Mb/s.
• Local port accepts 16 ST-BUS streams with data
rates of 2.048Mb/s, 4.096Mb/s, 8.192Mb/s or
16.384Mb/s, in any combination.
• Per-stream channel and bit delay for Local input streams.
• Per-stream channel and bit delay for Backplane input streams.
• Per-stream advancement for Local output streams.
• Per-stream advancement for Backplane output streams.
• Constant throughput delay for frame integrity.
• Per-channel high impedance output control for
Local and Backplane streams.Application• Central Office Switches (Class 5)
• Mediation Switches
• Class-independent switches
• Access Concentrators
• Scalable TDM-Based Architectures
• Digital Loop CarriersPinout
Specifications
|
Parameter |
Symbol |
Min |
Max |
Units |
| 1 |
Core Supply Voltage |
VDD_CORE |
-0.5 |
2.5 |
V |
| 2 |
I/O Supply Voltage |
VDD_IO |
-0.5 |
5.0 |
V |
| 3 |
PLL Supply Voltage |
VDD_PLL |
-05 |
2.5 |
V |
| 4 |
Input Volta |
VI_3V |
-0.5 |
VDD + 0.5 |
V |
| 5 |
Input Voltage (5V tolerant inputs) |
VI_5V |
-0.5 |
7.0 |
V |
| 6 |
Continuous Current at digital outputs |
LO |
|
15 |
mA |
| 7 |
Package power dissipation |
PD |
|
2 |
W |
| 8 |
Storage temperature |
TS |
-55 |
+125 |
°C |
DescriptionThe MT90870 has two data ports, the Backplane and the Local port. The Backplane port has two modes of operation, either 32 input and 32 output streams operated at 2.048Mb/s, 4.096Mb/s, 8.192Mb/s or 16.384Mb/s, in any combination, or 16 input and 16 output streams operated at 32.768Mb/s. The Local port of MT90870 has 16 input and 16 output streams operated at 2.048Mb/s, 4.096Mb/s, 8.192Mb/s or 16.384Mb/s, in any combination.
The MT90870 contains two data memory blocks (Backplane and Local) to provide the following switching path configurations:
• Backplane-to-Local, supporting 8K x 4K data switching,
• Local-to-Backplane, supporting 4K x 8K data switching,
• Backplane-to-Backplane, supporting 8K x 8K data switching.
• Local-to-Local, supporting 4K x 4K data switching.
The MT90870 contains two connection memory blocks, one for the Backplane output and one for the Local output. Data to be output on the serial streams may come from either of the data memories (Connection Mode) or directly from the connection memory contents (Message Mode).
In Connection Mode the contents of the connection memory defines, for each output stream and channel, the source stream and channel (stored in data memory) to be switched.
In Message Mode, microprocessor data of MT90870 can be written to the connection memory for broadcast on the output streams on a per channel basis. This feature is useful for transferring control and status information to external circuits or other ST-BUS devices.
The MT90870 uses a master frame pulse (FP8i) and master clock (C8i) to define the frame boundary and timing for both the Backplane port and the Local port. The device will automatically detect whether an ST-BUS or a GCI-BUSstyle frame pulse is being used. There is a two frame delay from the time RESET is de-asserted to the establishment of full switch functionality. During this period the frame format is determined before switching begins. The MT90870 provides FP8o, FP16o, C8o and C16o outputs to support external devices connected to the Local port. Subrate switching is accomplished by oversampling (i.e., 1 bit switching can be accomplished by sampling a 2 Mb/s stream at 16 Mbps). Refer to MSAN-175.
A non-multiplexed Motorola microprocessor port of MT90870 allows programming of the various device operation modes and switching configurations. The microprocessor port provides access for Register read/write, Connection Memory read/write and Data Memory read-only operations. The port has a 15-bit address bus, 16-bit data bus and 4 control signals. The microprocessor MT90870 may monitor channel data in the Backplane and Local data memories.
The mandatory requirements of the IEEE-1149.1 (JTAG) standard are fully supported via a dedicated test port. The MT90870 is manufactured in a 27mm x 27mm body, 1.27mm ball-pitch, 272-PBGA to JEDEC standard MS-034 BAL-2 Iss. A.
MT90870 Data Sheet
