Fault detection method of CPU (Central Processing Unit) module address and data bus

Abstract

The invention relates to a fault detection method of a CPU (Central Processing Unit) module address and a data bus, and belongs to the technical field of manufacture of electronic products. The fault detection method comprises the followings steps of: firstly, setting wires of all IO (Input / Output) ports of the CPU into low level output states before operating an RAM (Random Access Memory); secondly, sequentially heightening a data wire in a continuous address range of the RAM, writing data into the data wire, and carrying out read-back verification on the data wire to detect the conditions of short circuit and open circuit of the data bus of the CPU; thirdly, sequentially heightening the data wire, writing different data in which the low positions are different and the high positions are 0 into the RAM, and carrying out read-back verification; and fourthly, carrying out the same testing on the data in which the high positions are different and the low positions are 0 to detect the conditions of short circuit and open circuit of the data bus of the CPU as well as the short circuit condition between an address bus and the data bus. According to the fault detection method of the CPU module address and the data bus, the problem of faults of the addresses and data buses of the CPU module caused by plate-making and welding in a large-scale production process can be quickly and reliably detected.

Description

technical field [0001] The invention relates to a fault detection method for a CPU module address and data bus, belonging to the technical field of electronic product manufacturing. Background technique [0002] With the improvement of automation level, various automation equipments based on embedded computer technology are used more and more widely. In order to improve R&D efficiency and save production costs, the control core of automation equipment is usually modularized to form a common main control unit component, namely CPU module, which is used in various automation equipment with different functions. The CPU module is the computing core, and other functions such as application, driver, and interface are realized by the peripheral function expansion circuit board. The most basic part of CPU module hardware includes processor and off-chip memory based on bus expansion, in addition to IO port lines leading to the module interface. The multiplexed IO port line can be u...

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Problems solved by technology

[0004] The purpose of this invention is to provide a kind of fault detection method of CPU module address bus and data bus, to solve the current detection method of adjacent address and data bus on-off relationship, the CPU module address and data bus with disordered wiring cannot be detected The problem

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