 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
MT8980DE Datasheet(PDF) 4 Page - Mitel Networks Corporation |
|
||||||||||||||||||||||||||||||
MT8980DE Datasheet(HTML) 4 Page - Mitel Networks Corporation |
|
|
4 / 18 page  MT8980D 2-6 Functional Description In recent years, there has been a trend in telephony towards digital switching, particularly in association with software control. Simultaneously, there has been a trend in system architectures towards distributed processing or multi-processor systems. In accordance with these trends, MITEL has devised the ST-BUS (Serial Telecom Bus). This bus architecture can be used both in software-controlled digital voice and data switching, and for interprocessor communications. The uses in switching and in interprocessor communications are completely integrated to allow for a simple general purpose architecture appropriate for the systems of the future. The serial streams of the ST-BUS operate continuously at 2048 kbit/s and are arranged in 125 µs wide frames which contain 32 8-bit channels. MITEL manufactures a number of devices which interface to the ST-BUS; a key device being the MT8980 chip. The MT8980 can switch data from channels on ST- BUS inputs to channels on ST-BUS outputs, and simultaneously allows its controlling microprocessor to read channels on ST-BUS inputs or write to channels on ST-BUS outputs (Message Mode). To the microprocessor, the MT8980 looks like a memory peripheral. The microprocessor can write to the MT8980 to establish switched connections between input ST-BUS channels and output ST-BUS channels, or to transmit messages on output ST-BUS channels. By reading from the MT8980, the microprocessor can receive messages from ST-BUS input channels or check which switched connections have already been established. By integrating both switching and interprocessor communications, the MT8980 allows systems to use distributed processing and to switch voice or data in an ST-BUS architecture. Hardware Description Serial data at 2048 kbit/s is received at the eight ST- BUS inputs (STi0 to STi7), and serial data is transmitted at the eight ST-BUS outputs (STo0 to STo7). Each serial input accepts 32 channels of digital data, each channel containing an 8-bit word which may represent a PCM-encoded analog/voice sample as provided by a codec (e.g., MITEL’s MT8964). This serial input word is converted into parallel data and stored in the 256 X 8 Data Memory. Locations in the Data Memory are associated with particular channels on particular ST-BUS input streams. These locations can be read by the microprocessor which controls the chip. Locations in the Connection Memory, which is split into high and low parts, are associated with particular ST-BUS output streams. When a channel is due to be transmitted on an ST-BUS output, the data for the channel can either be switched from an ST-BUS input or it can originate from the microprocessor. If the data is switched from an input, then the contents of the Connection Memory Low location associated with the output channel is used to address the Data Memory. This Data Memory address corresponds to the channel on the input ST-BUS stream on which the data for switching arrived. If the data for the output channel originates from the microprocessor (Message Mode), then the contents of the Connection Memory Low location associated with the output channel are output directly, and this data is output repetitively on the channel once every frame until the microprocessor intervenes. The Connection Memory data is received, via the Control Interface, at D7 to D0. The Control Interface also receives address information at A5 to A0 and handles the microprocessor control signals CS, DTA, R/W and DS. There are two parts to any address in the Data Memory or Connection Memory. Figure 3- Address Memory Map A5 A4 A3 A2 A1 A0 HEX ADDRESS LOCATION 0 1 1 • • • 1 X 0 0 • • • 1 X 0 0 • • • 1 X 0 0 • • • 1 X 0 0 • • • 1 X 0 1 • • • 1 00 - 1F 20 21 • • • 3F Control Register * Channel 0† Channel 1† • • • Channel 31† * Writing to the Control Register is the only fast transaction. † Memory and stream are specified by the contents of the Control Register. |
Similar Part No. - MT8980DE |
|
Similar Description - MT8980DE |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
