KR20030065820A - Apparatus for expanding bus of micro control unit in telematic system - Google Patents

Abstract

PURPOSE: A bus expanding device for an MCU(Micro Control Unit) of a vehicle information terminal is provided to expand two I2C(Independent Integrated Circuit) buses of the MCU included in the vehicle information terminal to a plurality of SPI(Serial Peripheral Interface) buses. CONSTITUTION: An MCU(31) has an I2C bus system having two ports(clock port and data port). An I/O expander(32) connects to I2C buses of the MCU(31), and expands the I2C buses to SPI buses. Peripheral devices(33,34) connect to the SPI buses of the I/O expander(32). The I/O expander(32) has the first to nth expanders(32-1¯32-N) connected to the I2C buses of the MCU(31) for expanding the I2C buses to the SPI buses in parallel. Each of the first to nth expanders(32-1¯32-N) for changing the two ports(clock port and data port) of the I2C buses to four ports(clock port, input data port, output data port, and enable port) of the SPI buses and expanding the four ports of the SPI buses to a plurality of ports in parallel.

Description

Bus expansion unit of micro control unit of vehicle information terminal {APPARATUS FOR EXPANDING BUS OF MICRO CONTROL UNIT IN TELEMATIC SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bus expansion device of a micro control unit of an information terminal for a vehicle. Interface) The present invention relates to a bus expansion device of a micro control unit of an information terminal for a vehicle that can be extended to a bus.

In general, the vehicle information terminal mounted on the vehicle transmits the vehicle status information including the vehicle identification information and the location information to the central control system, and in the event of an accident, requests the rescue from the central control system using the status information. In the event of theft, the location of the stolen vehicle can be tracked using the identification number and location information of the vehicle, and when a portable computer such as a laptop is connected, the mobile internet network can be accessed.

A vehicle information terminal (TLELMATIC SYSTEM) for performing such a function is shown in Figure 1, Figure 1 is a general schematic diagram of a general vehicle information terminal, referring to Figure 1, from the GPS satellite through the GPS antenna ANT1 GPS receiver 11 for receiving GPS satellite signals including the vehicle's own location information, sensing unit 12 for detecting the state of various devices of the vehicle, and data input unit 13 for inputting data by a user ), Store and update sensing information, self-identification information and location information, control the processing according to data input, and control the transmission of vehicle status information, including vehicle identification information and location information, through the mobile communication network, etc. The micro control unit 14 controls various operations, and communicates with the central control system through the communication antenna ANT2 under the control of the micro control unit 14. A CDMA modem 15 for performing the operation, a display unit 16 for outputting a screen required for operation, a voice processing unit 17 for outputting the set information as a voice, and an RS-232C interface unit for connecting a PC. It contains 18.

In addition, the vehicle information terminal includes a power supply unit 19. The power supply unit 19 receives a voltage of approximately 12 V from the battery B1 of the vehicle, and provides an operating voltage V1 required for each unit of the apparatus ( 2.5V, 3.3V and 5V) and system backup voltage (VB1) (3.3V).

In such a vehicle information terminal, in order to add a function, an optional peripheral device must be added to the micro control unit 14. For example, in order to add a hand-leaf call function to a vehicle information terminal, peripheral devices such as a flash memory and a voice synthesizer for voice recording must be added.

FIG. 2 is an explanatory view of a bus system of a micro control unit of a conventional vehicle information terminal. Referring to FIG. 2, in order to add a peripheral device to a micro control unit of a conventional vehicle information terminal, the SPI bus is connected via a 4 SPI bus. A bus system that can control peripheral devices through four lines, wherein four lines are a clock (CLK), an input data (DI), an output data (DO), and an enable (EN).

However, in the case of using such an SPI bus system, since four ports must be assigned every time a peripheral device is added, there is a problem in that it is impossible to add a desired peripheral device in some cases, since the addition of peripheral devices is restricted.

In addition, in some cases, in order to add a peripheral device, there is a problem in that a separate microcomputer must be added.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and therefore, an object of the present invention is to provide a vehicle information terminal capable of extending two I2C buses of a micro control unit included in a vehicle information terminal to a plurality of SPI buses. The present invention provides a bus expansion device for a micro control unit.

1 is an overall schematic diagram of a general vehicle information terminal.

2 is an explanatory diagram of a bus system of a micro control unit of a conventional vehicle information terminal.

3 is a block diagram of a bus expansion apparatus of a micro control unit of a vehicle information terminal according to the present invention.

Explanation of symbols on the main parts of the drawings

31: micro control unit 32: I / O expander

33, 34: Peripheral devices 32-1 to 32-N: First to Nth I / O expanders

As a technical means for achieving the above object of the present invention, the apparatus of the present invention is a bus expansion device of a micro control unit of a vehicle information terminal, which adopts an I2C bus system having two ports, a clock port and a data port. A micro control unit 31; An I / O expander 32 connected to the I2C bus of the micro control unit 31 and extending this I2C bus to an SPI bus; And peripherals (33, 34) connected to the SPI bus of the I / O expander (32).

Hereinafter, with reference to the accompanying drawings, the configuration and operation of the bus expansion device of the micro control unit of the vehicle information terminal according to the present invention will be described in detail. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

3 is a configuration diagram of a bus expansion device of a micro control unit of a vehicle information terminal according to the present invention. Referring to FIG. 3, a bus expansion device of a micro control unit of a vehicle information terminal according to the present invention includes a clock port and a data port. A microcontrol unit 31 adopting an I2C bus system having two ports of I and an I / O expander which connects to the I2C bus of the microcontrol unit 31 and extends this I2C bus into an SPI bus ( 32 and peripheral devices 33 and 34 connected to the SPI bus of the I / O expander 32.

The I / O expander 32 is connected to the I2C bus of the micro control unit 31, and a plurality of first to NI / O expanders 32 extending the I2C bus in parallel to the SPI bus, respectively. Each expander includes two ports (clock port, data port) on the I2C bus and four ports (clock port, input data port, output data port, and enable port) on the SPI bus. At the same time, each of the four ports of the SPI bus is expanded in parallel.

The two ports of the I2C bus are a clock port and a data port, wherein the data port has eight start bits, eight address bits, one ACK bit, a plurality of data bits, and eight end bits.

First, the process of changing the data of the I2C bus into the data of the SPI bus in the I / O expander 32 will be described. The clock port of the I2C bus corresponds to the clock port of the SPI bus. And recognize one unit data according to a start bit included in data of the data port of the I2C bus, and provide an enable signal to a corresponding enable port according to the address bits included in the data of the data port of the I2C bus. In addition, one unit data included in the data of the data port of the I2C bus is provided corresponding to the output data of the SPI bus. Thereafter, data transmission is terminated according to an end bit included in data of the I2C bus.

Next, the process of changing the data of the SPI bus into the data of the I2C bus in the I / O expander 32 will be described. The clock port of the SPI bus corresponds to the clock port of the I2C bus. And the input data of the SPI bus corresponds to the data port of the I2C bus, a start bit before the data bit, an address bit between the start bit and the data bit, and an end bit after the data bit. Change the data on the SPI bus to the data on the I2C bus.

As described above, according to the present invention, by extending the bus by changing the data of the I2C bus to the data of the SPI bus, peripheral devices can be added almost indefinitely to a microcomputer such as a micro control unit.

The information terminal for a vehicle to which the present invention is applied as described above may include not only telematics but also a wireless transmission / reception terminal mounted on a vehicle. In addition, the present invention is not only a vehicle information terminal but also a low-orbit satellite transceiver such as a terminal. It can be applied to a system or a device using a microcomputer, such as a micro control unit.

According to the present invention as described above, it is possible to expand the two I2C bus of the micro control unit included in the vehicle information terminal to a plurality of SPI bus, there is a special effect that can add peripherals without limitation.

The above description is only a description of specific embodiments of the present invention, and the present invention is not limited to these specific embodiments, and various changes and modifications of the configuration are possible from the above-described specific embodiments of the present invention. It will be apparent to those skilled in the art to which the present invention pertains.

Claims (2)

In the bus expansion device of the micro control unit of the vehicle information terminal, A micro control unit 31 adopting an I2C bus system having two ports, a clock port and a data port; An I / O expander 32 connected to the I2C bus of the micro control unit 31 and extending this I2C bus to an SPI bus; And And a peripheral device (33, 34) connected to the SPI bus of the I / O expander (32). The method of claim 1, wherein the I / O expander 32 A plurality of first to Nth I / O expanders 32-1 to 32-N connected to the I2C bus of the micro control unit 31 and extending the I2C bus in parallel to the SPI bus, respectively; Each said expander Change the two ports of the I2C bus (clock port, data port) to four ports of the SPI bus (clock port, input data port, output data port and enable port), and each of the four ports of the SPI bus. Bus expansion device for a micro control unit of an information terminal for a vehicle, characterized in that a plurality of devices are extended in parallel.