Method for simulating low speed parallel interface by using GPIO (general purpose input output)

Abstract

The invention discloses a method for simulating a low speed parallel interface by using GPIO (general purpose input output). The method comprises the following steps of: dividing a GPIO pin of an interface conversion chip into a data pin and a control pin; defining the data pin as a data bus of the low-speed parallel interface; defining the control pin as a control bus of the low-speed parallel interface; controlling a GPIO data register and an input / output control register inside the interface conversion chip through a GPIO control module in a driving program of the interface through PCI e (periphery component interconnect express), so as to enable the data bus and the control bus to be at a working operation state of the low speed parallel interface.

Description

technical field [0001] The invention relates to the field of tax control, in particular to a method for simulating a low-speed parallel interface by using GPIO. Background technique [0002] Existing special hardware equipment for tax control, because of the continuation of the product, its core unit only has a low-speed parallel interface, and the low-speed parallel interface is transferred to a PCI slave interface through a conversion chip from a parallel port to a PCI (Peripheral Component Interconnect) interface , the transferred PCI slave interface is used as the overall external communication interface of the tax control equipment. When in use, the tax control equipment is installed on the PCI expansion slot of the microcomputer. [0003] With the development of computer bus technology, the expansion slot of the microcomputer will be replaced by PCIe (Peripheral Component Interconnect Express), so the PCI slave interface of the tax control equipment also needs to be up...

AI Technical Summary

Problems solved by technology

[0004] Generally speaking, replacing the interface conversion chip and using a new interface conversion chip to convert the low-speed parallel interface of the core unit into a PCIe slave interface can meet such upgrade needs, but no conversion chip with this function can be found in the market. Only conversion chips such as GPIO (General Purpose Input Output, general purpose input / output) converted from the PCIe slave interface can be found. The chip provides multiple control registers to realize the control of GPIO

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