I2C (inter-integrated circuit) equipment management method and complex programmable logic device (CPLD)

Abstract

The invention discloses an I2C (inter-integrated circuit) equipment management method. The method comprises the following steps of: distributing a sole equipment ID (identity) to I2C equipment of a host machine in a CPLD (complex programmable logic device) and configuring the corresponding relation between an SCL (serial clock line) group and an SDA (serial data line) analog switch group, where the equipment ID and the I2C equipment are located respectively; configuring the corresponding relation between every SCL group and a value of an SCL gate control register, and configuring the corresponding relation between every SDA analog switch group and the value of an SDA gate control register; and using the CPLD to receive the ID which is sent by an I2C controller and needs to access the I2C equipment through any bus and look up the SCL group and the SDA analog switch group, which correspond to the equipment ID, and gating an corresponding SCL and an SDA analog switch according to the configured corresponding relation. The invention further discloses the CPLD. According to the I2C equipment management method disclosed by invention, the multiple I2C equipment on one host machine equipment can be effectively managed.

Description

technical field [0001] The application relates to the field of data communication, in particular to a kind of I 2 C equipment management method and complex programmable logic device CPLD. Background technique [0002] I 2 The C (Inter-Integrated Circuit) bus is a simple bidirectional two-wire bus developed by PHILIPS for limited control between ICs (Integrated Circuit integrated circuit boards), including I 2 The serial clock line (SCL) of C and the I 2 C's serial data line (SDA) has two wires. [0003] With the development of communication technology, network devices such as routers and switches use I 2 There are more and more C-interface devices and devices, such as: memory sticks, optical modules, real-time clock chips (RTC), temperature sensors, 2 Various self-developed plug-in cards and sub-cards of C interface. [0004] I 2 There are two address formats of the C bus, 7-bit and 10-bit. Taking 7 bits as an example, theoretically an I 2 C bus can connect up to I ...

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Problems solved by technology

Taking 7 bits as an example, theoretically an I 2 C bus can connect up to I 2 C equipment can reach 128 (=2 7 ) pieces, but in fact due to the limitation that the total capacitance of the bus cannot exceed 400PF (picofarads), and most of the I 2 C devices are of the same type as these same types of I 2 The high 4-bit or 5-bit address of the C device is fixed, only the low 3-bit or low 2-bit address can be set, therefore, the same I 2 The same type of I that can be attached on the C bus 2 The number of C devices is very limited, only up to 8 (=2 3 ) or 4 (=2 2 )indivual

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