CN208000569U - A kind of digital quantity input/output unit based on expansible serial bus system - Google Patents

Abstract

The utility model is related to singlechip technology fields, specifically a kind of digital quantity input/output unit based on expansible serial bus system, it includes logic control element that described device is interior, acquired for realizing external signal and unwanted signals output interface is isolated, realizes isolation input interface and power supply that internal signal exports is isolated.The utility model has the beneficial effects that low cost, conveniently, each function module of the flexible expansion based on expansible serial bus system can not facilitate Host Extensions in original main machine structure as the external expansion devices of expansible serial bus system.

Description

A kind of digital quantity input/output unit based on expansible serial bus system

Technical field

The utility model is related to singlechip technology field, specifically a kind of digital quantity based on expansible serial bus system Input/output unit.

Background technology

In general SCM system, primary processor for realizing data calculating, signal acquisition, data storage etc. functions, But in most systems, resource can not meet system requirements in the piece of microcontroller, need to carry out respective extension, such as connect RAM (random access memory), EEPROM (band Electrically Erasable Programmable Read-Only Memory), FlashROM (the read-only programmings of flash Device), A/D converter (analog-digital converter), D/A converter (digital analog converter), LED display drivers, I/O interface chips, reality Shi Shizhong, UART transceiver etc. carries out module extension.

Under normal conditions, the extension of external module is generally carried out to microcontroller using bus mode, bus is divided into serial total Line and parallel bus are widely used in various data due to bus cable negligible amounts of universal serial bus, easily designed The fields such as storage, data acquisition, motion control.

Wherein, SPI (Serial Peripheral Interface (SPI)) bus is widely used in the design of plate grade device talk.Currently, each semiconductor Company is proposed a large amount of chip with various functions for carrying SPI interface, and extremely spirit is provided for the peripheral expansion of user Selection living and economic.In SCM system expansion process, each from the SPI interface of piece, it is only necessary to be connect from the I/O of main leaf Mouth draws four lines, this four lines are respectively clock line (CLK), downlink data line (MOSI), upstream data line (MISO), piece choosing Control line (CS).Wherein CLK lines, MOSI lines, MISO lines are common lines, that is to say, that all to be communicated between piece and main leaf This three lines are the same;And CS lines are then privte lines, that is to say, that be required for individually being equipped with when each communicating with main leaf from piece A piece CS line.To sum up, circuit design can be simplified using spi bus system, saves interface unit and I/O in many custom circuits Mouth line improves the reliability of design.

But from the description above in the drawbacks of capable of also summing up standard spi bus system.Since CS lines are privte lines, It is each required for individually being equipped with a CS line between piece and main leaf, this will make spi bus system be led in extension The limitation of piece I/O interface quantities, eventually leads to main leaf and can not connect and be more extended from piece, seriously limits the hair of system Malleability energy.

Application No. is " 201710238394.8 ", application publication number be " 107145460 A of CN ", entitled " one kind can expand The Chinese invention patent of exhibition serial bus system and its means of communication " discloses a kind of novel spi bus system comprising: One master controller, at least one from equipment and includes the universal serial bus of 5 cables at least one node selection logic module (clock line CLK, downlink data line MOSI, upstream data line MISO, piece select control line CS, address selection line CSA).The master Controller is connected to one end of 5 cables by interface, the node select logic module using T type modes access CS lines, CSA lines, CLK lines, MOS work lines, it is described that CLK lines, MISO cables are accessed using T-type mode from equipment, it is connected with master controller MOSI lines use daisy topology connection type, MOSI lines to select logic module to be connected to next stage node by this grade of node Select logic module and this grade from equipment, the node for being connected to this grade by CS lines from equipment selects logic module, institute The slave equipment stated is linked into using T-type mode between this grade of node selection logic module and downstream site selection logic module MISO cables.The invention solve because main leaf I/O port numbers it is limited caused by standard SPI systems can not dynamic expansion from The problem of piece.

This method is the improvement proposed to former master controller, but currently without a kind of in the premise for not changing former master controller Under, carry out the outer external expansion devices connected as with original host controller.

Utility model content

The purpose of the utility model is to overcome the deficiencies in the prior art, provide a kind of based on above-mentioned expansible universal serial bus The digital quantity input/output unit of system.

In order to achieve the above object, it is defeated to provide a kind of digital quantity based on expansible serial bus system for the utility model Enter output device, in described device including logic control element, acquired for realizing external signal and be isolated unwanted signals every From output interface, the isolation input interface and power supply of realization internal signal output;

Node is equipped in the logic control element selects logic port, the node that logic port is selected to be equipped with for connecting Meet the five of CS lines in expansible serial bus system on host, CAS lines, CLK lines, MOSI lines and MOSI lines this five cables A port, the node selection logic port have the node selection instruction discrimination module for being responsible for serial bus system, the section Signal and logic control element on point selection instruction discrimination module connection universal serial bus;

The output for being additionally provided in the logic control element and output interface is isolated connecting and realize digital output function Port and the input port that digital quantity input function is connect and realized with isolation input interface.

Preferably, node selection logic port connects host phase in above-mentioned serial bus system using T-type mode CS lines even, CAS lines, CLK lines, MOSI lines;

The node selection logic port connects the above-mentioned and universal serial bus system using daisy topology connection type The connected MOSI lines of host in system.

The utility model has the beneficial effects that low cost, conveniently, flexible expansion it is each based on expansible serial bus system A function module can not facilitate host as the external expansion devices of expansible serial bus system in original main machine structure Extension.

Description of the drawings

Fig. 1 is the structural schematic diagram of the utility model.

Wherein:

Output interface 3- isolation input interfaces are isolated in 1- logic control elements 2-

4- power supply 11- nodes select logic port 12- output ports

13- input ports

Specific implementation mode

Below in conjunction with the drawings and specific embodiments, the utility model is described further.

Embodiment 1:

A kind of digital quantity input/output unit based on expansible serial bus system as shown in Figure 1, in described device The isolation output interface 2 of unwanted signals is acquired and be isolated including logic control element 1, for realizing external signal, realizes inside The isolation input interface 3 and power supply 4 of signal output;

Node is equipped in the logic control element 1 selects logic port 11, node selection logic port 11 to be equipped with For connecting CS lines, CAS lines, CLK lines, MOSI lines and MOSI lines this five lines in expansible serial bus system on host There is the node selection instruction for being responsible for serial bus system to differentiate mould for five ports of cable, the node selection logic port 11 Block, the node selection instruction discrimination module are connected to signal and logic control element on universal serial bus;

The output for being additionally provided in the logic control element 1 and output interface is isolated connecting and realize digital output function Port 12 and the input port 13 that digital quantity input function is connect and realized with isolation input interface.

The node selection logic port 11 connects the CS that host is connected in above-mentioned serial bus system using T-type mode Line, CAS lines, CLK lines, MOSI lines;

The node selection logic port 11 connects the above-mentioned and universal serial bus using daisy topology connection type The connected MOSI lines of host in system.

The preferred embodiment created to the utility model above is illustrated, but the utility model is created not It is limited to the embodiment described, those skilled in the art can be under the premise of without prejudice to the utility model creative spirit Various equivalent modifications or replacement is made, these equivalent modifications or replacement are all contained in model defined by the application claim In enclosing.

Claims (2)

1. a kind of digital quantity input/output unit based on expansible serial bus system, which is characterized in that packet in described device Include logic control element (1), the isolation output interface (2) that is acquired for realizing external signal and unwanted signals are isolated, realize in The isolation input interface (3) and power supply (4) of portion's signal output;

It is equipped with node selection logic port (11) in the logic control element (1), is set on node selection logic port (11) It is useful for connecting CS lines, CAS lines, CLK lines, MOSI lines and MOSI lines this five lines in expansible serial bus system on host There is the node selection instruction for being responsible for serial bus system to differentiate mould for five ports of cable, the node selection logic port (11) Block, the node selection instruction discrimination module are connected to signal and logic control element on universal serial bus;

The output end for being additionally provided in the logic control element (1) and output interface is isolated connecting and realize digital output function Mouth (12) and the input port (13) that digital quantity input function is connect and realized with isolation input interface.

2. the digital quantity input/output unit according to claim 1 based on expansible serial bus system, feature exist In, node selection logic port (11) connected using T-type mode the CS lines that host is connected in above-mentioned serial bus system, CAS lines, CLK lines, MOST lines;

The node selection logic port (11) connects the above-mentioned and universal serial bus system using daisy topology connection type The connected MOSI lines of host in system.