Mitel MT90840 manual Detecting Clock Presence, Clock Quality and TM1 Tpcm Access Integrity

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MT90840

Preliminary Information

the DTA pin will be asserted (as the data is stored in the write-pipeline) but the next CPU access will not see DTA asserted. No clocks are necessary for register accesses (but if the write-pipeline is hung, the registers cannot be accessed). If the MT90840 is hung due to a CPU read of a memory with a missing clock, the hang can be cleared by ending the read access. If the MT90840 is hung due to a CPU write to a memory with a missing clock, the hang can be cleared by applying a hardware RESET to the MT90840.

Detecting Clock Presence

After it is set, the BPE bit is cleared within 2 frames of the C4/8 clock (i.e. within 250 μsec). If this bit is cleared by the MT90840, the CPU can deduce that the C4/8 clock is present. In TM3, in TM4, and in TM2 with INTCLK asserted, C4/8 is internally generated from PCKR, and if the BPE bit is cleared by the MT90840, the CPU can deduce that the PCKR clock is present.

Clock Quality and TM1 TPCM Access Integrity

In Timing Mode 1 the parallel transmit frame pulse PPFTo must be held in phase with the serial bus frame pulse input (F0i). This is performed automatically by the MT90840 with an internal correction event, which moves the PPFTo output. In normal TM1 operation the correction happens once on initialization, and does not happen again as long as the C4/8 and PCKT clocks stay phase-locked.

If the clocks lose their phase lock, the MT90840 will assert an automatic correction, and set the TXPAA interrupt bit high. The transmit parallel port data, the CTO control data and the TX frame pulse (PPFTo) will all jump phase due to this correction, causing one errored TDM frame.

If a CPU write to the Transmit Path Connection Memory is occurring during the one PCKT clock cycle that clocks the correction, there is a chance that the write data will go to address 0, rather than the intended address. To avoid this it is necessary to keep clocks stable during TPCM programming in TM1 (including not using DIN while programming). If there is some doubt about the quality of the clocks in a particular application, options include:

-1- Program the TPCM in TM2, or TM2 with internal clocks (INTCLK=1), where this clock correction does not occur.

-2- Monitor the TXPAA interrupt bit during TPCM programming, and check the intended address, and address 0, if a TXPAA alarm occurs.

-4- Read/verify address 0 after a block of TPCM writes. If address 0 is corrupted, one of the writes occurred during a clock correction.

Clock Quality and TM2 RPCM Access Integrity

In Timing Mode 2 the serial frame pulse F0o must be held in phase with the parallel port RX frame pulse (PPFRi). This is performed automatically by the MT90840 with an internal correction event, which inverts the phase of the SPCKo output. In normal operation the correction happens once on initialization, and does not happen again as long as the C4/8 and PCKR clocks stay phase-locked.

If the clocks lose their phase lock, the MT90840 will assert an automatic correction, and set the RXPAA interrupt bit high. The serial port data and the ST bus frame pulse (F0o) will jump phase due to this correction, causing one errored TDM frame. The PPCE bit indicates a change in framing at the receive parallel port which may cause a “cascade” correction at SPCKo.

If a CPU write to the Receive Path Connection Memory is occurring during the one 4.096 MHz clock cycle that clocks the correction, there is a chance that the write data will go to Stream0-Channel0, or Stream1-Channel0, rather than the intended address. To avoid this it is necessary to keep clocks stable during RPCM programming in TM2 (including not using DIN while programming). If there is some doubt about the quality of the clocks in a particular application, options include:

-1- Program RPCM in TM1, where this correction does not occur.

-2- Program RPCM in TM2 with Internal Clock mode, (INTCLK=1) where this correction does not occur. -3- Monitor the RXPAA interrupt bit during RPCM programming, and check the ST0-Ch0 and ST1-Ch0 addresses if an alarm occurs.

-4- Read/verify ST0-Ch0 and ST1-Ch0 after a block of RPCM writes. If either is corrupted, one of the writes occurred during a clock correction.

Memory Block-Programming

The MT90840 allows the user to program one value into the entire Transmit Path Connect Memory High, or Receive Path Connect Memory High, with a single register write. This feature allows the four most significant bits of each byte in the TPCM High, or RPCM High, to be automatically programmed with the value of the 4 PBD bits of the GPM register. This eases system initialization by allowing all channels to be placed in high-impedance, or all channels to be placed in bypass. The procedure works as follows:

a)The SEL2-0 bits in the Control Register are used to select Block-Programming for either the TPCM High, or the RPCM High blocks. It is also necessary to select the serial port mode (with

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Contents Features ApplicationsPIN Plcc Pin ConnectionsDescription 100 Pin DescriptionPin # No ConnectionPckt PckrTDI +5 Volt Power Supply GroundFunctional Description Time Slot Interchange Operation SwitchingDevice Operation PPFRi PDi0-7 C4/8R1&2 4 MHz Serial I/O 2 MbpsSerial I/O 4 Mbps C4/8R1&2 8 MHz Serial I/O 8 Mbps Pckr or Pckt TCP bit = PPFTi/o Ppfp bit =1 PDo0-7Transmit Path Bypass/Parallel-Switching PathReceive Path Serial Data Port Serial Frame Pulse Parallel Port Clock Signals and FramingParallel Data Port Timing Mode 1 TM1 Ring Master Timing and Switching ControlOutput Driver Enable Control Capability Asynchronous Parallel Port With ST-BUS Clock MasterTM1 Multiple-MT90840 Sub-Mode Pfdi Timing Mode 2 TM2 Ring SlaveAsynchronous Parallel Port With ST-BUS Clock Slave Internal 4.096 MHz Clock Divider External PLL and C4 Phase-CorrectionTM2 Multiple-MT90840 Sub-Mode Sfdi Sfdi = Synchronous Parallel Port With ST-BUS Clock SlaveSfdi = MT90840 Per-channel Bypass on the Parallel Port MT90840 Throughput DelayMT90840 Per-channel Functions Per-channel Control Outputs on the Parallel PortMode Data Rates Minimum Delay Total Throughput Delay MT90840 Throughput Delay SummaryPer-channel Tri-state Serial and Parallel Per-channel Message Mode Serial and ParallelSTi0 STo0 Per-channel Direction Control on the Serial PortSerial Data Memory Addressing Addressing2.048 Mbps Add/Drop Mode Tpdm Addressing IRQ Interrupt Pin Microprocessor PortAddress Mapping of the Internal Registers DTA Data Transfer Acknowledgment PinHex Accessing Internal MemoriesMT90840 Register Address Mapping Detecting Clock Presence Clock Quality and TM1 Tpcm Access IntegrityClock Quality and TM2 Rpcm Access Integrity Memory Block-ProgrammingTiming Mode Initialization Jtag SupportI01 Instruction Description Test Access Port TAPBoundary-Scan Instruction Register Boundary-Scan Instruction RegisterBoundary-Scan Register Cells Definitions Test Data RegistersCells Definition HighRegister Description Interface Mode Selection Register IMS READ/WRITETiming Mode Register TIM READ/WRITE DR1General Purpose Mode Register GPM READ/WRITE Alarm Status Register ALS READ/WRITEPhase Status Registers PSD Read Only Control Register CR READ/WRITEInternal Memory Description AB9 AB8AB11 AB10 Distributed Isochronous Network CTI Distributed Architecture Implemented with the MT90840Characteristics Sym Min Typ‡ Max Units Test Conditions/Pins Parameter Symbol Min Max UnitsCharacteristics Sym Min Typ Max Units Test Conditions Absolute Maximum RatingsCharacteristics Sym Min Typ‡ Max Units Test Conditions TM1Units Test Conditions Characteristics Sym Min Typ‡Output Pin Test Point Serial Port with Negative Polarity F0 ST-BUS Serial Port with Positive Polarity F0 GCISerial Port Timing for 2.048 Mbps TM2 SFDi = 0 and TM3 267 F0 Frame Sync with Negative Polarity Spfp = F0 Frame Sync with Positive Polarity Spfp =Serial Port Timing for 8.192 Mbps TM1 and TM2 SFDi = Frame Sync with Positive Polarity Spfp = Frame Sync with Negative Polarity Spfp =Timing for the Parallel Port External Control Lines CTo0-3 AC Electrical Characteristics Parallel Data Port Parallel Port Receive TimingParallel Port in Timing Mode RD/WR 774 Up to 3 C4 cycles + Register takd-wrIntel/National Multiplexed Bus Timing AD0AC Electrical Characteristics† Motorola Multiplexed Bus Mode Characteristics Sym MinAD0-7 AD0-13Parameter Symbol Min Max Units Test Conditions Boundary Scan Test Port TimingDim Min Max Dimensions in inches are not exactNot to scale 280

MT90840 specifications

The Mitel MT90840 is an advanced telecommunications device designed to enhance connectivity and communication capabilities for various applications. With its robust array of features and technologies, the MT90840 is well-suited for businesses looking to improve their communications infrastructure.

One of the standout features of the Mitel MT90840 is its integration of voice and data services. This allows users to manage their communications more efficiently, streamlining operations and reducing costs. The device supports a wide range of voice codecs, ensuring high-quality audio during calls and providing flexibility for users who may require different standards for different applications.

Another key characteristic of the MT90840 is its scalability. The device is designed to grow with the needs of a business. It supports multiple lines and can be configured to handle an increasing number of users without compromising performance. This scalability is particularly advantageous for organizations that may undergo growth or changes in their communication needs over time.

The Mitel MT90840 also incorporates advanced networking technologies, such as VoIP (Voice over Internet Protocol). This allows users to make voice calls using the internet rather than traditional phone lines, reducing costs for long-distance calls and improving overall communication efficiency. The device is equipped with features that support secure, encrypted communication, further protecting sensitive data and conversations from potential breaches.

Additionally, the MT90840 is designed with user-friendliness in mind. It features an intuitive interface that simplifies operation, making it accessible even for those who may not be tech-savvy. The device is compatible with various peripherals, such as headsets and conferencing equipment, further enhancing its usability in diverse settings, from small offices to large conference rooms.

Moreover, the Mitel MT90840 offers excellent interoperability with a variety of third-party applications. This flexibility enables organizations to integrate the device into their existing systems seamlessly, thereby enhancing productivity without requiring a complete technological overhaul.

In conclusion, the Mitel MT90840 stands out as a versatile and reliable telecommunications solution. Its rich feature set, including voice and data integration, scalability, VoIP capabilities, user-friendly interface, and interoperability, makes it an ideal choice for businesses looking to elevate their communications strategy.
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