MT8950 Mitel Networks Corporation, MT8950 Datasheet
MT8950
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MT8950 Summary of contents
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... NRZo SPi ISO-CMOS ST-BUS MT8950AC Description The MT8950 is a coder/decoder which uses the Transition Encoded Modulation (TEM) technique for encoding/decoding low speed data to and from a 56/ 64 kbps channel (equivalent to PCM Voice). coding and decoding scheme is transparent and can accept either synchronous or asynchronous data kbps (inclusive) ...
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... MT8950 ISO-CMOS Pin Description Pin # Name 1 CSTi Control ST-BUS In (TTL Input) - This ST-BUS interface pin accepts a serial input stream which loads the Control Register. device, the bits in the Violation word, and, the resetting of Data Activity (DA) and Scan Point output (SPo) are controlled by this register. The contents of the register are updated once every ST-BUS frame when the interface is enabled ...
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... HIGH (RZ format), outputs unipolar, active low SPACE pulses connection connection. 22 PRST Power Reset (CMOS Schmitt Input ) - A LOW level on this input evokes the power reset condition for the codec connection Positive Supply Voltage +5 volts ± 10 MT8950 ISO-CMOS Description 1 pin - the data format and 6-5 ...
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... MT8950 ISO-CMOS Theory of Operation The MT8950 is an encoder/decoder which operates on low baud rate data (up to 19.2 kbps) to convert it to the ST-BUS format. The data can subsequently be transparently switched or transmitted in a manner identical to PCM encoded voice. In this respect, the functional characteristics of the device are very similar to many industry standard voice codecs ...
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... EX-ORed and the result in combination with the remaining bits of the TEM word is used to reproduce the original data with an accuracy of ± 3.906µs (see Table 2). Due to the data speed restriction above 8 kbps, the second and third transitions (if any) will be reproduced at MT8950 ISO-CMOS 0 Frame Type b7 b ...
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... MT8950 ISO-CMOS intervals which are multiples of 52µs (depending upon the input data baud rate). Functional Description The functional block diagram of the data codec is shown in Figure 1. The low speed data to be encoded is accepted by the NRZ/RZ input circuitry and relayed to the encoder. The 8 bit encoded word is transmitted within one channel time period on to the ST-BUS serial output stream ...
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... Figure 11. All data input and output at the ST-BUS interface takes place at 2.048 Mbps Nom. or 104 s. Nom. or > 125 s MARK SPACE 125 s. Min. 125 s. Min. MARK SPACE 2 on the remote end X MT8950 ISO-CMOS Bit Period b 125 s. Min 125 s. Min. 125 s. Min ...
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... MT8950 ISO-CMOS The Secondary Clock input (SCLK) is normally a 600Hz clock signal. This clock is internally aligned with the 2.048 MHz input used to generate the synchronizing pulses and the violation word timing (when the chip is operating in the local carrier mode). Note that the 600Hz frequency is an exact multiple of the most commonly used baud rates, i ...
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... CRB3 CRB4 1.67 0=1.67 msec 1.67 1.67 msec 1=3.33 msec msec msec CRB2 MT8950 ISO-CMOS This output is set The external circuitry The NRZ/RZ data input to the T =0.7RC SP is the duration of the SPACE long SPACE of 150ms is To detect this signal, a and C equal to 1.0µ ...
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... MT8950 ISO-CMOS The SPo pin could then be monitored by the system processor to detect a prompt from the peripheral. MT8950 +5V SPo R SPi 11 NRZo C Figure 7 - Long Space Detection Circuit External Power Reset When the reset input (PRST) is taken low, the data codec circuit goes into reset mode. The conditions ...
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... MT8950 ISO-CMOS 1 input on the Codec one channel the system channel During this same time period 1 pin. This signal is level R If this input is tied MT8950 1 24 CSTi DSTi C2i PRST 4 21 DSTo NC ...
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... Receiver AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA MT8950 Receiver DSTi D 2 Bipolar to X Unipolar D 1 Converter X DSTo Unipolar Bipolar Converter Line Driver ...
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... 2.25 2 ±1 ±10 IN MT8950 ISO-CMOS ) unless otherwise stated. Min Max Units -0.5 7.0 V -0 -0 ± 10 ± 20 ± 25 ± 50 -65 150 1.0 ) unless otherwise stated. SS Units Test Conditions V MHz o C Units Test Conditions µ ...
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... MT8950 ISO-CMOS DC Electrical Characteristics =5.0V±10%; V =0V Voltages are with respect to ground ( Characteristics 1 Output LOW voltage 2 Output HIGH Voltage 3 Output LOW Current (On all O outputs except DSTo Output HIGH Current (On all P outputs except DSTo Output LOW Current (On ...
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... AAAA AAAA AAAA AAAA AAAA t PLZ t PZH t CF AAAA AAAA AAAA PHL ISH MT8950 ISO-CMOS AAAA AAAA AAAA AAAA AAAA AAAA AA AAAA AAAA AAAA AAAA AAAA AAAA AA AAAA AAAA AAAA AAAA AAAA AAAA AA AAAA AAAA ...
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... MT8950 ISO-CMOS NOTES: 6-18 ...