WO2012097569A1

WO2012097569A1 - Method and apparatus for accessing i2c device

Info

Publication number: WO2012097569A1
Application number: PCT/CN2011/076424
Authority: WO
Inventors: 李建锋
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-01-21
Filing date: 2011-06-27
Publication date: 2012-07-26
Also published as: CN102081570B; CN102081570A

Abstract

A method and an apparatus for accessing I2C devices are provided to improve efficiency and stability of the access to the I2C devices and reduce the load of a CPU. The method for accessing the I2C devices includes: an automatic polling module accesses periodically for specific I2C devices which are predetermined to need frequent access according to a preset access period, and buffers and updates access results for each of the specific I2C devices in real time; and an active access module reads the data of the specific I2C devices from a buffer region directly or accesses the I2C devices except the specific I2C devices according to a user request.

Description

Method and device for accessing I2C device

The present invention relates to the field of communications technologies, and in particular, to an access method and apparatus for an Inter-Integrated Circuit (I2C) device. Background technique

The I2C (also denoted C or _IIC ) bus is a two-wire serial bus used to connect the microcontroller to its peripherals. Currently, the I2C bus is primarily used in server management, including communication of individual component states. For example, an administrator can query individual components to manage the configuration of the system or to master the functional status of the components, such as power supplies and system fans. It can monitor multiple parameters such as memory, hard disk, network, system temperature, etc. at any time, which increases the security of the system and facilitates management.

Among them, the device managed by the I2C bus is called an I2C device. In the field of current communication technologies, I2C devices have become more and more widely used.

So-called I2C devices, such as: Small Form Factor Pluggable (SFP) in PON (Passive Optical Networks) „ In many PON systems, multiple SFP optical modules need to be frequently performed. Access, in order to get timely information on the received light power, current voltage, temperature, etc. In addition, real-time monitoring of signal loss (LOS, Loss of Signal) signals, and so on.

In the prior art, access to the I2C device is simply implemented by the CPU or only by the programmable logic device. Therefore, the above-mentioned frequent access operations on the SFP optical module and the like undoubtedly impose a heavy burden on the access system of the I2C device, thereby reducing the access efficiency, reliability, and other performance of the system. Summary of the invention

The embodiments of the present invention provide an access method and device for an I2C device, which can improve the access efficiency of the I2C device, stability of access, and reduce the burden on the CPU.

An access method of an I2C device provided by an embodiment of the present invention includes:

The automatic polling module periodically accesses a predetermined specific I2C device that needs frequent access according to a preset access period, and caches and updates the access result for each specific I2C device in real time;

The active access module reads data of a specific I2C device directly from the buffer area according to a user request, or accesses an I2C device other than a specific I2C device.

An access device for an I2C device provided by an embodiment of the present invention includes:

The automatic polling module is configured to periodically access a predetermined specific I2C device that needs frequent access according to a preset access period, and cache and update the access result for each specific I2C device in real time;

The active access module is configured to read data of a specific I2C device directly from a buffer area according to a user request, or access an I2C device other than a specific I2C device.

In the embodiment of the present invention, the automatic polling module periodically accesses a predetermined specific I2C device that needs frequent access according to a preset access period, and caches and updates the access result for each specific I2C device in real time; The user requests to read the data of a specific I2C device directly from the buffer area or access the I2C device other than the specific I2C device. The invention avoids simply accessing the I2C device by the CPU or the programmable logic device alone, but combines the characteristics of both, and accesses the frequently accessed device registers to the automatic polling module, thereby greatly reducing the access. The burden of active access module (CPU), improved access efficiency to I2C devices, and stability of access ensure efficient and stable operation of the entire system. DRAWINGS

FIG. 1 is a schematic diagram of a connection relationship between modules according to an embodiment of the present invention; 2 is a schematic structural diagram of an access device of an I2C device according to an embodiment of the present invention; FIG. 3 is a schematic diagram of logic implementation of a CPLD as an I2C timing implementation module according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of state transitions when each module is switched by using a CPLD according to an embodiment of the present invention; FIG.

FIG. 5 is a schematic flowchart diagram of an access method of an I2C device according to an embodiment of the present invention. detailed description

The embodiments of the present invention provide an access method and device for an I2C device, which are used to improve the access efficiency of the I2C device, the stability of the access, and the burden on the CPU.

The technical solution provided by the embodiment of the present invention is applied to an access to an I2C device, and requires a system device with high stability, high reliability, and high efficiency.

The technical solution provided by the embodiment of the present invention provides a flexible, efficient, and reliable access method and device for a system including multiple I2C devices and requiring frequent access to the I2C devices to obtain a large amount of real-time data, thereby reducing the system. The complexity, save CPU resources, and better ensure the system's efficiency, stability and reliability.

The device provided by the embodiment of the present invention is mainly composed of an active access module, an automatic polling module, and an I2C timing implementation module. The connection relationship between the modules in the device and the connection relationship with the I2C device are shown in FIG. 1 . among them,

The active access module can be implemented by a CPU, a single chip microcomputer, a digital signal processing (DSP) device, etc., and is used to access an I2C device by calling an I2C timing realization module according to a user request.

The automatic polling module, which can be implemented by programmable logic devices, is mainly used to automatically poll some I2C devices to obtain real-time data information of these I2C devices. The I2C device that the module needs to access frequently and the registers in the I2C device can be flexibly configured according to user requirements, so that frequent accesses of these registers are implemented by the automatic polling module. In the embodiment of the present invention, the I2C device accessed by the automatic polling module is referred to as a specific I2C device. Other than this, the I2C device can be called a normal I2C device.

The I2C timing implementation module is an implementation module of the specific timing of the I2C protocol specification, and is used to access the I2C device according to the control of the automatic polling module or the active access module. Access to all I2C devices is ultimately done through the I2C timing implementation module.

The user has the flexibility to select the specific I2C device in the automatic polling module that needs to be polled, as well as the specific registers in the particular I2C device, ie, which of the I2C devices need to be automatically accessed by the automatic polling module. For example, some frequently accessed registers can be set to be accessed by the auto-poll module.

In general, the auto-polling module continuously polls the specific I2C devices identified by the user that require frequent access and feeds the results back into a specific data buffer. When the active access module needs to access these I2C devices accessed by the automatic polling module, the corresponding access result can be obtained directly from the data buffer in the automatic polling module.

In addition, if the active access module needs to access a register other than the specific register of the specific I2C device accessed by the automatic polling module, the automatic polling module can release the I2C bus, hand the I2C bus to the active access module, and access the active access module. Once completed, the auto-poll module takes over the I2C bus again and continues polling. This allows flexible switching between the active access module and the automatic polling module.

Specifically, referring to FIG. 2, an access device of an I2C device according to an embodiment of the present invention includes: an automatic polling module 101, configured to perform periodicity on a predetermined specific I2C device that needs frequent access according to a preset access period. Sexual access, cache and update the access results for each specific I2C device in real time.

The active access module 102 is configured to read data of a specific I2C device directly from a buffer area according to a user request, or access an I2C device other than a specific I2C device.

Preferably, the active access module 102 includes:

The normal I2C device access unit 201 is configured to be outside the specific I2C device according to the user request. The I2C device is accessed.

The specific I2C device access unit 202 is configured to access a specific I2C device according to a user request.

Preferably, the specific I2C device access unit 202 obtains the access result of the specific I2C device from the cache of the automatic polling module 101 according to the user request, and feeds back to the user.

Preferably, the device further comprises:

The I2C timing implementation module 103 is configured to access the I2C device according to the control of the automatic polling module 101 or the active access module 102.

The normal I2C device access unit 201 notifies the automatic polling module 101 to release the I2C bus, and determines that the automatic polling module 101 suspends the access of the I2C timing implementation module to all the specific I2C devices; and calls the I2C timing implementation module 103 through the I2C bus. The I2C device other than the specific I2C device that the user needs to access is accessed, and the access result is obtained; the automatic polling module 101 is notified that the I2C bus is available;

The automatic polling module 101, when receiving the notification of releasing the I2C bus sent by the active access module 102, suspends the access of the I2C timing implementation module 103 to all the specific I2C devices; when receiving the I2C bus sent by the active access module 102 When the notification is available, the access to the I2C timing implementation module 103 is invoked for all specific I2C devices.

Preferably, the active access module 102 is a CPU, a single chip microcomputer or a digital signal processor; the automatic polling module 101 and the I2C timing implementation module 103 are programmable logic devices.

The access method of the I2C device provided by the embodiment of the present invention will be described in detail below by taking the access to the multi-channel SFP optical module in the PON system as an example.

For example, the active access module is implemented by the CPU, and the automatic polling module and the I2C timing implementation module according to the embodiment of the present invention are implemented by a Complex Programmable Logic Device (CPLD). The I2C device that needs to be accessed is an SFP optical module. The automatic polling module is mainly used to poll the LOS alarm information of the SFP optical module.

When the user wants to obtain the register information of some ordinary SFP optical modules, it only needs to pass the main The access module and the I2C timing implementation module can access the registers of the corresponding SFP optical modules, and the flow is similar to the existing process.

When the automatic polling module accesses the SFP optical module, the automatic polling module can pre-configure the SFP optical module number to be accessed, the SFP optical module register address, the SFP optical module address AO or A2, the read operation code and the write operation code, and Access period.

For each visit, see Figure 3, which specifically includes:

The automatic polling module determines information such as the start register address of this access, the data length of this access, and the data value to be written (only for write operations).

The automatic polling module determines whether the access is a read operation or a write operation;

If it is a read operation, the automatic polling module determines the SFP optical module address AO or A2 that is accessed this time, and the read operation flag;

The I2C timing implementation module is enabled to access the SFP optical module.

The automatic polling module determines whether the current access is complete. If yes, it determines whether the current access is successful. If successful, the data information of the SFP optical module is read. If not, the failure reason is obtained, and the failed result is returned to the user. Cause; if the access is not completed, continue to wait; if it is a write operation, the automatic polling module determines the SFP optical module address AO or A2 that is accessed this time, and the write operation flag;

The automatic polling module determines the data to be written;

The automatic polling module determines whether the current access is completed. If yes, it determines whether the current access is successful. If successful, the current access is ended. If the access is not successful, the reason for the failure is obtained, and the reason for the failure is returned to the user; If the visit is not completed, continue to wait.

Among them, a CPLD register can be specifically set to store information about whether the access is successful, and if the access fails, the reason for the access failure is recorded.

When the user wants to access the LOS information of the SFP optical module, the automatic polling module is configured to poll the LOS alarm information of the SFP optical module. Therefore, you can directly access the automatic wheel Query the cache in the module. Because the automatic polling module accesses the SFP optical module without interruption, and updates the access result data to the corresponding cache, that is, each SFP optical module corresponds to one cache, and the automatic polling module reads the LOS information of each SFP optical module. And write the read data to the cache corresponding to the SFP optical module.

The state transition between the automatic polling module and the active access module, as shown in Figure 4, specifically includes:

First, in the normal state, the I2C bus is occupied by the automatic polling module, and the automatic polling module is in the automatic working state (STATE_AUTO_WORK).

Then, when the user initiates the active access module for access, the automatic polling module stops all access actions and releases the I2C bus. At this time, the automatic polling module is in the automatic stop state (STATE_AUTO-STOP).

After the active access module obtains the I2C bus usage right, it enters the main working state (STATE MAIN WORK) and starts to access the I2C device.

Finally, the active access module re-delivers the I2C bus to the auto-poll module and proceeds to step one. This cycle.

In summary, referring to FIG. 5, an access method of an I2C device provided by an embodiment of the present invention includes the following steps:

Step 501: The automatic polling module periodically accesses a predetermined specific I2C device that needs frequent access according to a preset access period, and caches and updates the access result for each specific I2C device in real time.

Step 502: The active access module directly reads data of a specific I2C device (for example, directly reads a value of a specific register of a specific optical module) from a buffer according to a user request, or accesses an I2C device other than a specific I2C device.

Preferably, the method further includes:

The active access module accesses specific I2C devices based on user requests.

Preferably, the active access module accesses a specific I2C device according to a user request, include:

The active access module obtains the access result of the specific I2C device from the cache of the automatic polling module according to the user request, and feeds back to the user.

Preferably, the active access module accesses the I2C device other than the specific I2C device according to the user request, including:

The active access module notifies the automatic polling module to release the I2C bus, and determines that the automatic polling module suspends access to the I2C timing implementation module for access to all specific I2C devices;

The active access module invokes the I2C timing implementation module through the I2C bus to access the I2C device other than the specific I2C device that the user needs to access, and obtains the access result;

The active access module notifies the automatic polling module that the I2C bus is available.

Preferably, the active access module is a CPU, a single chip microcomputer or a digital signal processor; the automatic polling module and the I2C timing implementation module are programmable logic devices.

The technical solution provided by the embodiment of the present invention avoids simply accessing the I2C device by the CPU or the programmable logic device alone, but combines the characteristics of the two to transfer the frequently accessed device registers to the programmable logic device. Access, which greatly reduces the burden on the CPU, improves the access efficiency of the I2C device, and the stability of the access, ensuring efficient and stable operation of the entire system.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the invention can be embodied in the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) including computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to general purpose computers, Using a processor of a computer, embedded processor or other programmable data processing device to generate a machine such that instructions executed by a processor of a computer or other programmable data processing device are generated for implementing one or more of the flowcharts A flow and/or block diagram of a device in a box or a plurality of functions specified in a plurality of blocks.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram. The spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims

Claim

A method for accessing an I2C device, the method comprising:

2. The method according to claim 1, wherein the method further comprises: the active access module accessing a specific I2C device according to a user request.

The method according to claim 2, wherein the active access module accesses the specific I2C device according to the user request, including:

The method according to claim 1, 2 or 3, wherein the active access module accesses an I2C device other than the specific I2C device according to the user request, including: the active access module notifies the automatic polling module Release the I2C bus and determine that the auto-poll module suspends access to the I2C timing implementation module for access to all specific I2C devices;

5. The method of claim 4, wherein

The active access module is a CPU, a single chip microcomputer or a digital signal processor;

The automatic polling module and the I2C timing implementation module are programmable logic devices.

6. An access device for an I2C device, the device comprising:

Automatic polling module, used for frequent visits to predetermined needs according to a preset access period Asking specific I2C devices for periodic access, caching and updating the access results for each particular I2C device in real time;

The device according to claim 6, wherein the active access module comprises: a normal I2C device access unit, configured to access a specific I2C device according to a user request

I2C device access;

A specific I2C device access unit for accessing a specific I2C device according to a user request.

The device according to claim 7, wherein the specific I2C device access unit is configured to obtain an access result of the specific I2C device from the cache of the automatic polling module according to the user request, and feed back to the user. .

The device according to claim 7 or 8, wherein the device further comprises: an I2C timing implementation module, configured to access the I2C device according to the control of the automatic polling module or the active access module;

The common I2C device access unit is specifically configured to notify the automatic polling module to release the I2C bus, and determine that the automatic polling module suspends calling the I2C timing implementation module to access all the specific I2C devices; and the I2C timing is used to implement the module to the user through the I2C bus. Accessing I2C devices other than the specific I2C device that needs to be accessed, and obtaining access results; notifying the automatic polling module that the I2C bus is available;

The automatic polling module is specifically configured to: when receiving the notification of releasing the I2C bus sent by the active access module, suspending the access of the I2C timing implementation module to all the specific I2C devices; when receiving the I2C bus sent by the active access module At the time of notification, the call to the I2C timing implementation module is restored to access all of the specific I2C devices.

10. Apparatus according to claim 9 wherein:

The active access module is a CPU, a single chip microcomputer or a digital signal processor; The automatic polling module and the I2C timing implementation module are programmable logic devices.