IO expansion chip

Abstract

The invention discloses an IO expansion chip, and relates to the field of electronic technology, electrical control and PLC automatic control. According to the invention, an IO configuration module sets a chip IO pin selection specific configuration as a required input configuration or output configuration; the IO input acquisition filtering module is configured to be selectively connected to an external Pin pin of the chip; the IO output control module outputs the control information written by the MCU to an IO output pin; the interface mode of the MCU communication interface module is a Spi / iic serial communication mode; and the IO driving module outputs a control signal to drive and amplify. According to the invention, the expansion of multiple IO units is achieved, and the expansion ofthe IO units is not limited; input or output can be configured as required, so that the utilization rate of chip pins is improved; the input acquisition loop has an efficient digital filtering function, so that the signal reliability is enhanced; and the output has protection logic and enhanced driving design, so that the requirements of complex control and driving are met.

Description

technical field [0001] The present invention relates to the fields of electronic technology, electrical control, and PLC automatic control, in particular, it is used to expand IO ports in embedded control systems and microprocessor systems, and to collect such as button states, over-temperature alarms, and loop closure states Instructions or status information, and output control signals to execution units such as relays, contactors, motor control, door switches, LED light arrays, etc., especially involving an IO expansion chip. Background technique [0002] In electronic products and control equipment systems controlled by microprocessors, it is often necessary to collect and output a large number of IO digital signals. However, microprocessors often have limitations in the number of IO pins and driving characteristics. When more IOs or stronger driving capabilities are required, IO expansion or an additional IO expansion chip is required. The methods include, for example,...

AI Technical Summary

Problems solved by technology

However, in the specific implementation method, sampling the peripheral IO interface that comes with the CPU, or using a general IO expansion chip to realize the real-time logic of this type of protection, it is difficult to meet the real-time requirements for program operation and processing relying on the CPU, so generally The practice is to use an additional peripheral control circuit to realize the hardware logic protection that detects the blockade. For this reason, the hardware circuit becomes complicated, and the consistency of its control and the flexibility of parameter adjustment are also limited by hardware characteristics and hardware parameters. , and reduces the reliability

Moreover, the general IO expansion chip has low driving capability, and the continuous current is generally less than 10mA

Driving common loads such as relays requires external expansion of driver chips or circuits, which will continue to increase the complexity of system hardware circuits

[0006] In addition, the general IO expansion chip has a fixed pin configuration, the number of input and output ratios and pin positions, which is not conducive to improving the utilization of the pins and is not convenient for wiring.

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