A plc program executor ip core

Abstract

The invention discloses an IP (intelligent property) core of a PLC (programmable logic controller) program performer. The intelligent core is hitched on an on-chip bus through a bus interface, and meanwhile, an MCU (microprogrammed control unit) and a storage are hitched on the on-chip bus. The IP core comprises a bus interface module, a program counting module, an instruction reading module, an addressing module, a data fetching module and a performing module. The bus interface module comprises a plurality of registers. The PLC program is an IL (intermediate language) program, and is stored in a 32bit fixed-length instruction set format. The IP core is hitched on the on-chip bus through the bus interface, receives control signals through the registers, reads IL instructions from the storage hitched on the on-chip bus and cooperates with the registers to execute the instructions through each module. The IP core can execute the PLC program efficiently at fast speed; and due to structural design of the IP core, performance affections and defects relative to hardware due to the fact that the PLC program execution only relies on the MCU are avoided, and the interface is open and easy to transplant.

Description

technical field [0001] The invention relates to a program execution module implemented on a chip, in particular to a PLC program executor IP core. Background technique [0002] With the development of automatic control technology, programmable logic controller (PLC) has been more and more used in various industries, and the standardization level is getting higher and higher. At present, a series of international standards (IEC61131) such as the typical structure of PLC controllers, programming languages, communications, and user guidelines have been formed. Among them, the programming language standard (IEC61131-3) is the most widely used, and all programmable controllers need to support the five languages ​​supported by the standard, including IL, ST, LD, FBD and SFC. Among them, the IL language is the instruction list statement, which is the language closest to the PLC machine language (similar to assembly language), and the other four are high-level languages. Gener...

AI Technical Summary

Problems solved by technology

Replace a MCU processor chip, or only upgrade a PLC internal component, the original configuration programming software may no longer be applicable

Therefore, its versatility is poor, and the cost of product application and upgrade is high

In addition, similar to the interpreted execution method, although the compiled execution method compiles the PLC program into local code, it still needs to adopt the reduced instruction set format of the general-purpose processor, and each IL instruction may require 3-10 local assembly instructions ; Even if other PLC languages ​​(such as FBD, ST) are directly compiled into local assembly instructions (without passing through IL intermediate code), local assembly is not oriented to the instruction set structure of PLC programs after all, and there is still an inevitable loss of efficiency

[0005] On the other hand, in the PLC controller structure with MCU as the processing core, both interpreted and compiled types require a lot of work from the MCU, and the MCU usually needs to complete other important tasks (such as communication, display), PLC tasks The execution and response speed of the MCU are also affected by other work of the MCU, and it is difficult to guarantee its real-time and reliability

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