KR20070022807A - Filtering Digital Diagnostics Information In An Optical Transceiver Prior To Reporting To Host - Google Patents

Abstract

The present invention relates to an optical transceiver 100 configured to filter digital diagnostics before the filtered results can be connected to a host computing system 111 (hereinafter simply referred to as a "host") that is communicatively coupled to the optical transceiver 100. It is about. The optical transceiver 100 includes sensor (s) 211A-C for measuring analog operating parameter signals such as temperature and supply voltage. Analog signals are each converted into a plurality of digital samples by analog-to-digital converter (s) 214. Processors 203A-B execute microcode that causes the optical transceiver 100 to perform filtering on various samples. Thereafter, the optical transceiver 100 may enable the filtered result to be connected to the host 111.

Optical transceiver, digital diagnostic information filtering, microcode

Description

Filtering Digital Diagnostics Information In An Optical Transceiver Prior To Reporting To Host}

The present invention generally relates to optical transceivers and optical transceiver host computing systems (hereinafter simply referred to as "hosts"). More specifically, the present invention relates to filtering diagnostic information for an optical transceiver before reporting the filtered information to the host.

Computing and networking technologies have changed the world. As the amount of information delivered over the network increases, high-speed transmission becomes even more important. Many high speed data transmission networks rely on optical transceivers and similar devices that facilitate the transmission and reception of digital data implemented in the form of optical signals over optical fibers. Thus, optical networks are found in a wide variety of high speed applications, ranging from the appropriate ones like small local area networks (LANs) to the huge ones like the backbones of the Internet.

In general, data transmission in such a network is performed by an optical transmitter (also called an electro-optic transducer) such as a laser or light emitting diode (LED). The electro-optic transducer emits light when current passes through, and the intensity of the emitted light is a function of the magnitude of the current passing through the transducer. Data reception is generally performed by an optical receiver (also called an optoelectronic transducer), an example of which is a photodiode. The optoelectronic transducer receives light and generates a current, the magnitude of the generated current being a function of the intensity of the received light.

Various other components are used by the optical transceiver to assist in the control of the optical transmitting and receiving components and the processing of various data and other signals. For example, such optical transceivers generally include an electro-optical transducer driver (eg, referred to as a "laser driver" when used to drive a laser signal) configured to control the operation of the optical transmitter in response to various control inputs. Optical transceivers also generally include amplifiers (eg, sometimes referred to as "post amplifiers") configured to perform various operations on certain parameters of the data signal received by the optical receiver. Control circuitry (hereinafter referred to as "controller") controls the operation of the laser driver and post amplifier.

In addition, the controller may also include various sensors capable of measuring transceiver operating parameters. There may also be sensors coupled to the laser driver, post amplifier and other transceiver components. These operating parameters may include temperature, transceiver voltage, laser bias current, transmit and receive power, and the like.

During operation of the optical transceiver, it is often useful to carry out the diagnosis of the various operating parameters. A common way in which diagnostics are carried out is to have sensor measurement and operating parameter values and transmit them to an analog to digital converter, which may be in a controller or may be an individual transceiver component. The analog to digital converter converts the value into a digital signal and reports the value to a host computing system coupled to the transceiver module. This allows the user to evaluate various operating parameters.

However, there is a problem with performing the diagnosis in this way. For example, reported values may not be very stable. Due to electrical, thermal or mechanical noise in or around the transceiver, operating parameters are susceptible to the resulting range. This means that there may be a large difference in the first reported values compared to the second reported values. For example, even if the temperature conditions are relatively stable, the temperature of the first reported value may be 80 ° C, the temperature of the secondary reported values may be 70 ° C, and the temperature of the third reported value may be 76 ° C. . This can often lead to uncertainty about what the operating temperature is actually. This is especially a problem when there are defined operating standards that must be met for special operating parameters.

Thus, an optical transceiver capable of providing more accurate digital diagnostic information to the host may be advantageous.

The above-mentioned problems with the state of the art are overcome by the principles of the present invention with respect to an optical transceiver configured to perform digital diagnostic filtering before providing a filtered value to a host computing system that can be communicatively coupled to the optical transceiver. do. The optical transceiver includes a system memory and at least one processor.

The optical transceiver measures an analog operating parameter signal. These analog signals may include transceiver temperature, transceiver voltage, laser bias current, transmit and receive power, and the like. The optical transceiver then obtains digital samples from the analog signal for use in filtering.

Microcode is loaded into system memory. When executed by a processor, the microload causes the transceiver to perform filtering operations on digital samples. The filtering can be performed in any manner useful for extracting useful diagnostic information from the sample. While the principles of the present invention are not limited to any particular type of filtering operation, examples include simple averaging by which the processor adds together parameter values and the like and then divides by the added number to obtain a filtered value. In another embodiment, an infinite impulse response (IIR) filter or a finite impulse response (FIR) filter may be implemented in either hardware or software (or a combination of hardware and software) to perform the filtering operation. When executed in software, the operation may be driven by microcode loaded into system memory. After the filtering operation, the transceiver can make the filtered results accessible to the host.

Accordingly, the principles of the present invention provide digital diagnostic filtering prior to a transceiver that enables digital diagnostic information to be accessible to a host. This saves valid host computing resources for other host operations. Also, many hosts do not have access to enough samples for reliable filtering. This may be due to the slow communication channel between the host and the transceiver. The filtering is also much more efficient since the optical transceiver allows for faster and more efficient access to the samples and the optical transceiver itself performs the filtering. Finally, users are provided reliable diagnostics without the need for additional host computing hardware such as additional processors.

The above-mentioned advantages and other advantages and features of the present invention are shown in the following description, and in part will be apparent from the description, or may be learned by practice of the present invention. The features and advantages of the invention may be realized and attained by means and combinations particularly pointed out in the claims. These and other features of the present invention are more fully understood from the following specification and claims, or may be learned by practice of the invention as shown below.

BRIEF DESCRIPTION OF DRAWINGS To make the above mentioned and other advantages and features of the present invention clearer, more specific description of the invention is made with reference to the specific embodiments shown in the accompanying drawings. It is understood that these drawings only describe specific embodiments of the invention and therefore should not be considered as limiting the scope of the invention. The invention is described and described with additional specificity and detailed description through the use of the accompanying drawings.

1 schematically illustrates an example of an optical transceiver capable of realizing the features of the present invention.

2 schematically illustrates an example of the control module of FIG. 1.

3 illustrates a flow chart of an optical transceiver method for performing filtering on a digital diagnosis prior to reporting a result to a host computing system in accordance with the principles of the present invention.

The principles of the present invention relate to an optical transceiver configured to perform filtering for digital diagnostics before the filtered result can be connected to a host computing system (hereinafter simply referred to as a "host") coupled to communicate with the optical transceiver. The optical transceiver includes sensor (s) for measuring analog operating parameter signals such as temperature and supply voltage. Then, each analog signal is converted into a plurality of digital samples by analog to digital converter (s). Run microcode to allow the optical transceiver to filter on various samples. The optical transceiver can then make the filtered result accessible to the host. This may be done by the host polling the transceiver for the filtered results and / or the transceiver logging the filtered results directly to the host. An exemplary operational optical transceiver environment is described first. The operation according to the invention is then described with respect to the operating environment.

1 illustrates an optical transceiver 100 in which the principles of the present invention may be employed. Although the optical transceiver 100 will be described in more detail, the optical transceiver 100 is described by way of example only and is not intended to limit the scope of the invention. The principles of the present invention are suitable for 1G, 2G, 4G, 8G, 10G and larger bandwidth fiber links. Moreover, the principles of the present invention can be realized in any form factor optical (eg laser) transmitter / receiver without limitation, such as XFP, SFP, and SFF. In this case, the principles of the present invention are not limited to any optical transceiver environment.

The optical transceiver 100 receives the optical signal from the optical fiber 110A using the receiver 101. The receiver 101 acts as an optoelectronic transducer by converting an optical signal into an electrical signal. Receiver 101 provides the resulting electrical signal to post-amplifier 102. Post-amplifier 102 amplifies the signal and provides the amplified signal to external host 111 as indicated by arrow 102A. The external host 111 may be any computing system capable of communicating with the optical transceiver 100. External host 11 may include host memory 112, which may be a volatile or nonvolatile memory source. In one embodiment, the optical transceiver 100 may be a printed circuit board or other component / chip in the host 111, although not required.

The optical transceiver 100 may also receive an electrical signal from the host 111 for transmission to the optical fiber 110B. In particular, the laser driver 103 receives an electrical signal as indicated by arrow 103A and causes the transmitter 104 to emit an optical signal representing the information in the electrical signal provided by the host 111 onto the optical fiber 110B. The transmitter 104 (eg, a laser or a light emitting diode (LED)) is driven together with the signal. Thus, the transmitter 104 serves as an electro-optic transducer.

The operation of the transceiver 101, the post amplifier 102, the laser driver 103, and the transmitter 104 may vary dynamically due to various factors. For example, temperature variations, power variations, and feedback conditions can affect the performance of these components, respectively. Accordingly, the optical transceiver 100 evaluates the operating environment different from the temperature and voltage conditions, and receives information from the post amplifier 102 (as indicated by arrow 105A) and from the laser driver 103 (as indicated by arrow 105B). It includes a control module 105 that can receive the information of. This allows the control module 105 to optimize the dynamic variable performance and additionally detect if there is a signal loss.

In particular, the control module 105 may also offset these changes by adjusting the settings for the post amplifier 102 and / or the laser driver 103 as indicated by arrows 105A and 105B. These setting adjustments are quite intermittent because they are only guaranteed if the temperature or voltage or other low frequency changes. Receive power is an example of such a low frequency change.

The control module 105 may be connected to the permanent memory 106, which in one embodiment is an electrically erasable and programmable read only memory (EEPROM). Permanent memory 106 and control module 105 may be packaged together in the same package or in a different package without limitation. Permanent memory 106 may also be any other nonvolatile memory source.

The control module 105 includes both an analog unit 108 and a digital unit 109. Together, they allow the control module to perform logic digitally while still interacting primarily with the rest of the optical transceiver 100 using analog signals. 2 schematically illustrates an example 200 of a control module 105 in more detail. The control module 200 includes an analog unit 200A representing an example of the analog unit 108 of FIG. 1 and a digital unit 200B representing an example of the digital unit 109 of FIG. 1.

For example, the analog portion 200A may be a digital analog converter, an analog digital converter, a high speed comparator (eg, for event determination), a voltage based reset generator, a voltage regulator, a voltage reference, a clock generator, and other analog It may include parts. For example, analog portion 200A includes sensors 211A, 211B and 211C, among other possible ones, as indicated by ellipsis 211D. Each of these sensors can measure operating parameters that can be measured from the control module 200, such as supply voltage and transceiver temperature, for example. The control module may also be an external analog or digital signal from other components in the optical transceiver that represent other measured parameters such as, for example, laser bias current, transmit power, receive power, laser wavelength, laser temperature, and thermoelectric cooler (TEC) current. Can be received. While two external lines 212A and 212B are shown for receiving such an external analog signal, there may be many such lines.

The internal sensor can generate an analog signal representing the measured value. In addition, the externally provided signal may also be an analog signal. In this case, the analog signal is converted into a digital signal to be used in the digital unit 200B of the control module 200 for future processing. Of course, each analog parameter value can have its own analog to digital converter (ADC). However, to conserve chip space, each signal can be periodically sampled in round robin form using a single ADC, such as the ADC 214 shown. In this case, each analog value may be provided to the multiplexer 213 which selects one of the analog signals at one time by the ADC 214 for sampling in continuous form. Alternatively, the multiplexer 213 may be programmed to cause an analog signal of any magnitude to be sampled by the ADC 214.

As mentioned above, the analog portion 200A of the control module 200 also includes, for example, a digital analog converter, another analog digital converter, a high speed comparator (eg, for event detection), a voltage based reset generator, a voltage regulator, a voltage Other analog components 215 such as a reference, clock generator, and other analog components. The digital unit 200B of the control module 200 may include a timer module 202 that provides various timing signals used by the digital unit 200B. Such timing signals may include, for example, programmable processor clock signals. The timer module 202 can also operate as a watchdog timer.

Also included are two general purpose processors 203A and 203B0, which follow a particular instruction set and are common general purpose such as shifting, branching, adding, subtracting, multiplying, dividing, Boolean operations, comparison operations, and the like. Recognize instructions that may perform an operation In one embodiment, general purpose processors 203A and 203B are each 16-bit processors and may be configured identically.The instruction set may be optimized based on a particular hardware environment and Since the exact hardware environment is not important to the principles of the present invention, the exact structure of the instruction set is not important to the principles of the present invention.

The host communication interface 204 is possibly implemented using a two-wire interface such as I ² C shown in FIG. 1, such as a serial data (SDA) line and a serial clock line on the optical transceiver 100. It is used to communicate with the host 111. Other host communication interfaces may also be implemented. Data may be provided from the control module 105 to the host 111 using this host communication interface to enable digital diagnostics and reading such as temperature levels, transmit and receive power levels, and the like. External device interface 205 is used to communicate with other modules within optical transceiver 100, such as post-amplifier 102, laser driver 103, or permanent memory 106, for example.

Not to be confused with external permanent memory 106, internal control system memory 206 may be RAM or nonvolatile memory. The memory controller 207 shares a connection to the controller system memory 206 among the respective processors 203A and 203B and a connection between the host communication interface 204 and the external device interface 205. In one embodiment, the host communication interface 204 includes a serial interface controller 201A, and the external device interface 205 includes a serial interface controller 201B. The two serial interface controllers 201A and 201B may be communicated using a two-wire interface such as I ² C or may be another interface as long as the interface is recognized by both communication modules. One serial interface controller (eg, serial interface controller 201B) is a master component, while the other serial interface controller (eg, serial interface controller 201A) is a slave component.

The input / output multiplexer 208 multiplexes various input / output pins of the control module 200 with respect to various components in the control module 200. This allows other components to dynamically allocate pins according to the existing operating environment of the control module 200. Thus, there may be more I / O nodes in the control module 200 than there are pins available on the control module 200 to reduce the footprint of the control module 200.

Register set 209 includes many individual registers. These registers may be used by the processor 203 to write microcode generated data that controls the high speed comparison in the optical transceiver 100. Alternatively, the register may hold data for selecting operating parameters for comparison. In addition, the resistor may be a memory that maps to various components of the optical transceiver 100 that control aspects of components such as laser bias current or transmit power.

Having described a particular environment with reference to FIGS. 1 and 2, it is understood that this particular environment is one of many structures in which the principles of the present invention may be employed. As mentioned above, the principles of the present invention are not intended to be limited to any particular environment.

According to the present invention, the optical transceiver performs filtering on various operating parameters. Operating parameters can be measured from various analog sensors in the optical transceiver. The optical transceiver converts each analog signal into a plurality of digital samples and receives microcode in system memory that, when executed by the optical transceiver processor, causes the optical transceiver to filter the plurality of samples. The optical transceiver can then make it accessible to a host computing system (hereinafter simply referred to as a "host") in which the filtered results can be coupled to communicate with the optical transceiver.

Referring to FIG. 3, a flow diagram of a method 300 of performing adjustments to digital diagnostics before an optical transceiver reports results to a host is shown. The optical transceiver may first obtain a plurality of digital samples from the analog signal representing the digital diagnostic information (step 301). This can be done by having the optical transceiver analog sensor measure the analog signal. The sensor may provide the analog signal to an analog to digital converter for sampling to produce digital samples.

The optical transceiver loads microcode from various sources into system memory (step 302). The microcode may be loaded from a remote computing system coupled to the host or optical transceiver via a network such as permanent memory, a host, or the Internet. The microcode may also be loaded from any other source capable of providing microcode to the optical transceiver. As shown in FIG. 3, the order in which the optical transceiver performs steps 301 and 302 is not critical to the principles of the present invention. Operation may occur in parallel or either of steps 301 and 302 may occur first.

The processor then executes the microcode (operation 303). When the microcode is executed by the processor (s) of the optical transceiver, the optical transceiver performs the operations shown in step 303 when executed. In particular, the processor may connect a digital sample (step 321), perform a filtering operation on the digital value (step 322), and then optionally make the filtered results accessible to a host (step 323). .

Specific embodiments are described with reference to the environments described and illustrated with respect to FIGS. 1 and 2. Referring to FIG. 1, the transceiver 100 is shown as being able to be communicatively coupled to the host 111. In this specification and claims, two entities may be "combined in communication" where they can be combined in communication with each other. In this specification and claims, “combined in communication” is defined as being capable of delivering data in either one or both directions.

2, analog sensors 211A, 211B, and 211C are shown. As used herein, an "analog sensor" is defined as any device capable of making analog measurements and generating corresponding analog signals. As discussed above, analog sensors 211A, 211B, and 211C may be configured to measure various analog operating parameters of optical transceiver 100, such as transceiver temperature and supply voltage. These analog sensors generate an analog signal corresponding to the measured parameter value and send the signal to the multiplexer 213. For example, if the sensor 211A is configured to measure temperature, an analog signal corresponding to the measured temperature is transmitted to the multiplexer 213.

It may also be desirable to measure analog operating parameters external to the control module 105. These may include laser bias current, transmit power, receive power, and the like. The analog sensor can be coupled to the post amplifier 102 and the laser driver 103 to ensure the measurement of certain operating parameters. For example, an analog sensor coupled to laser driver 103 can measure laser bias current or other laser operating parameters. The analog sensor can also be coupled to any part of the optical transceiver 100 to make the desired measurement. External measurement results are transmitted to the multiplexer 213 via external connection lines 212A and 212B. As mentioned above, there may be many additional external leads required for the number required for the measured parameters.

2, an analog to digital converter 214 is shown. Analog-to-digital converter 214 converts the input analog signal into a corresponding output digital value. The digital value can then be sampled by the processor 203 and used in the filtering operation as described below.

Processors 203A and 203B are general purpose processors capable of performing general purpose operations such as addition and division necessary to perform filtering. Processors 203A and 203B are coupled to permanent memory 106 via an external device interface 205. Permanent memory 106 may include microcode that, when executed by either processor 203A or 203B, causes processor 203 to perform filtering operations on digitally converted values. The microcode is loaded from permanent memory 106 into controller system memory 206, and the processor 203 executes this microcode and starts the filtering operation.

In one embodiment, the filtering operation consists of adding a predetermined number of digital value samples and dividing the sum by the sum of the digital samples. The number of filtered samples depends on the speed of the processor 203. In this embodiment, the processor 203 may filter 32, 64, and 128 digital samples. However, a large number of digital fountains can be filtered by selecting the appropriate fast processor 203. Processor 203 stores each digital sample in memory, such as a register in register set 209, until all 32, 64, and 128 samples are obtained from digital to analog converter 214. Processor 203 then accesses the digital sample and adds the value and divides it into 32, 64 and 128, depending on the number of values added.

In another embodiment, an Infinite Impulse Response (IIR) filter or a Finite Impulse Response (FIR) filter may be implemented in hardware, software, or a combination thereof to perform the filtering operation. When executed in software, the operation can be driven by microcode loaded into system memory. IIR filtering and FIR filtering are well known techniques in the field of digital signal processing. Thus, the IIR filter and the FIR filter can be implemented by any technique known to those skilled in the art of digital signal processing.

Microprocessors 203A and 203B receive microcode from permanent memory 106 or other permanent memory source, as described above. In addition to instructing the processor 203 to perform the filtering operation, the microcode can also instruct the processor 203 so that the filtered results connect to the host 111. This may be done by a host that polls the transceiver for results filtered by the host and / or a transceiver that logs the filtered results directly to the host. The filtered results facilitate the retrieval of operating parameters by the user by allowing access to the host. This also allows the host 111 to use the filtered data in other user defined actions.

Thus, the principles of the present invention provide an optical transceiver that filters digital diagnostics prior to communicating with a host computer system. This results in many measurements used in the filtering operation to compensate for any anomalies in the individual measurements, producing very stable and reliable results. The results sent to the host are no longer filtered by the host and can be evaluated directly. This frees up host computing system resources for other tasks and enables accurate measurements without the time spent processing other hosts or users. In addition, there is no need to add larger or additional processors to the host. Thus, the principles of the present invention represent a major advance in the art of optical transceivers.

The invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive. Accordingly, the scope of the invention is indicated by the claims rather than the foregoing specification. All modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Included in the Detailed Description of the Invention.

Claims (18)

An optical transceiver comprising a system memory and at least one processor and capable of being coupled in communication with a host computing system, the method comprising: filtering digital diagnostic information before the optical transceiver communicates with the host computing system; Obtaining a plurality of samples from the analog signal, Loading microcode into system memory, Executing the microcode using a processor to cause the optical transceiver to perform a next filtering operation; Filtering the plurality of samples prior to communicating with a host computing system. The method of claim 1, And making the filtered results connectable to the host computing system. The method of claim 1, Filtering the sample Adding the plurality of samples together to form a sum; Dividing the sum by the number of samples added together to form a filtered result. The method of claim 1, Filtering the sample comprises performing the filtering by use of an Infinie Impulse Response (IIR) filter. The method of claim 1, Filtering the sample comprises performing the filtering by use of a Finite Impulse Response (FIR) filter. The method of claim 1, And wherein the analog signal is one of transceiver temperature, transceiver supply voltage, laser bias current, transceiver receive power, or transceiver transmit power. The method of claim 1, And wherein the optical transceiver is one of a 1G laser transceiver, a 2G laser transceiver, a 4G laser transceiver, an 8G laser transceiver, or a 10G laser transceiver. The method of claim 1, And wherein said optical transceiver is a laser transceiver suitable for an optical fiber link larger than 10G before communicating with a host computing system. The method of claim 1, And wherein said optical transceiver is one of an XFP laser transceiver, an SFP laser transceiver, or an SFF laser transceiver. At least one processor, An analog to digital converter configured to obtain a plurality of samples from the analog signal, Having system memory with microcode, And wherein the microcode is configured to, when executed by the at least one microprocessor, cause the optical transceiver to perform a filtering operation on the plurality of samples to access a plurality of samples to generate a filtered value. The method of claim 10, And cause the filtered result to be connected to a host computing system coupled to the optical transceiver. The method of claim 10, Performing the filtering operation is adding a plurality of samples together to form a sum and dividing the sum by the number of samples added together to form a filtered value. The method of claim 10, Performing the filtering operation includes the use of an infinite impulse response (IIR) filter. The method of claim 10, The performance of the filtering operation includes the use of a finite impulse response (FIR) filter. The method of claim 10, Wherein the analog signal is one of transceiver temperature, transceiver supply voltage, laser bias current, transceiver receive power, or transceiver transmit power. The method of claim 10, The optical transceiver is one of a 1G laser transceiver, a 2G laser transceiver, a 4G laser transceiver, an 8G laser transceiver, or a 10G laser transceiver. The method of claim 10, The optical transceiver is a laser transceiver suitable for an optical fiber link larger than 10G. The method of claim 10, The optical transceiver is one of an XFP laser transceiver, an SFP laser transceiver, or an SFF laser transceiver.

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