JPH0870323A - Mode setting device - Google Patents

Abstract

PURPOSE: To facilitate selective use corresponding to the use of a user by providing a switching means for switching and selecting output signals from a serial/ parallel data conversion means and a setting data generation means. CONSTITUTION: A serial/parallel I/F circuit 1 uses signals CS, SK and SI supplied from terminal ports 1-3 as the minimum of three control lines to be required in serial communication. The circuit 1 turns supplied serial changeover control data to mode changeover control data for setting modules 1-4 and supplies them to the side of the terminal (a) of respective changeover switches SW1-SW4. In this mode setting device, by respectively linking and switching the four switches SW1-SW4, for instance, so as to fall down on the side of the terminal (a) corresponding to system selection signals supplied through the terminal SERIAL/XPARALLEL of an LSI, the mode changeover control data are supplied to the respective modules 1-4. Thus, fine mode control required by peripheral circuits for communication is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to mode switching compatible with mode setting by both serial and parallel methods, and more particularly to a mode setting device suitable for use in setting an internal operation mode of an LSI.

[0002]

2. Description of the Related Art Conventionally, as a method of setting an internal mode of an LSI, for example, a parallel method in which pins of the LSI are directly connected to a logic circuit is switched, and a circuit in which data captured in the LSI is switched by using serial communication is used. There is a serial method to connect.

The mode setting by the parallel method is firstly the simplest as a control method, and secondly, can be performed by a circuit or system simple structure such as a switch and a port of a microcomputer. It has the feature that it can.

Another mode setting by the serial method is that serial switching control data for controlling the mode can be supplied by using serial communication.
Even when performing various mode controls, serial data SI,
That is, for example, the serial switching control data, the serial clock signal SCK, the communication state selection signal CS, and at least three control lines make it possible to perform various controls.

[0005]

By the way, in the mode setting by the parallel system, when trying to control various modes, for example, the LSI requires the number of input pins according to the mode. However, circuits such as LSI require a large number of signal lines such as data input pins and adjustment signals for conforming to the signal standard in addition to mode setting input pins. The maximum number of input pins that can be used for mode setting is also limited. This limitation on the number of pins limits the number of controllable modes.

Further, the mode setting by the serial system is
The limit of the data that can be communicated indicates the limit of the controllable mode. More specifically, the limit of communicable data is, for example, when the VTR is communicated once per field, the serial clock SC supplied from the outside is used.
Since the communication length is limited by the condition of K,
There is a limit to the mode settings.

Further, in this mode setting by the serial system, a control circuit such as a microcomputer is required externally for transmitting the data for controlling the mode. For this reason, this system has a slightly complicated configuration both in terms of circuitry and system.

As described above, the mode setting of each method has advantages and disadvantages according to each. here,
When considering a product form using an LSI, one of these two mode setting methods is selected in order to realize the same function. As described above, it is necessary to properly use the above-mentioned two LSI methods according to the control mode selected by the user.

However, it becomes necessary to provide a plurality of types of LSIs in accordance with the control mode selected by the user, resulting in additional man-hours for development of the LSI.

Therefore, the present invention has been made in view of the above situation, and an object of the present invention is to provide a mode setting device that can be selectively used according to the application of the control mode, that is, the communication system.

[0011]

A mode setting device according to the present invention sets a serial / parallel I / F circuit for converting supplied serial switching control data into parallel switching control data, and setting from the supplied switching control data. Decoding circuit for generating mode signal and serial / parallel I / F
It is characterized in that it has a changeover switch for selectively selecting an output signal from the circuit and the decoding circuit.

[0012] Here, the changeover switch is changed over in association with a changeover selection signal indicating a serial system / parallel system supplied corresponding to a plurality of modules.

[0013]

In the mode setting device according to the present invention, the data supplied to the serial / parallel I / F circuit is supplied to one end of the changeover switch as serial changeover control data for each module, and is supplied to the decode circuit. By supplying the parallel changeover control data output corresponding to the data to the other end side of the changeover switch, and changing over the changeover switch according to the serial system / parallel system changeover selection,
For example, the switching control data supplied through the same pin in the LSI is set to a mode by the communication of each selected method, and one LSI performs the usage according to the user's application, that is, the method.

The changeover switch is combined with the mode of each module by switching in conjunction with a changeover selection signal indicating a serial system / parallel system that is supplied corresponding to a plurality of modules. Make settings.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the mode setting device according to the present invention will be described below with reference to the drawings. Here, the mode setting device will be described based on an example of a case where the mode setting corresponding to the parallel method and the serial method can be performed for the setting of the internal mode of the LSI or the like.

For example, as shown in FIG. 1, the LSI includes, for example, four modules therein, a serial / parallel I / F circuit 1 for converting serial switching control data supplied in a serial system into parallel data, and a parallel system. Decoding circuit 2 for generating mode setting data from the parallel switching control data supplied in step S1 and switching switch SW for switching and selecting the switching control data between the serial system and the parallel system.
And have.

Module 1 (MOD1) has modes 1 to 1
It is a module that functions in correspondence with three kinds of mode settings of mode 3. Module 2 (MOD2) is in Mode A
It is a module that functions in correspondence with the four types of mode setting of mode D. In addition, module 3 (MOD3)
Module 4 (MOD4) is a module that functions in correspondence with two types of mode settings, mode X and mode Y.
Is a module that functions in correspondence with three types of mode settings, mode L to mode N. Therefore, this LSI
Depending on the possible combinations, it has 3 × 4 × 2 × 3 = 72 functions.

This LSI is provided with a terminal port 1 to which a serial communication state selection signal CS is supplied, a terminal port 2 to which a clock signal used in the serial system is supplied,
The terminal port 3 to which the serial switching control data signal SI of the serial system is supplied, the terminal ports 4 to 6 named NC to indicate that they are not connected in the serial system, and either one of the serial system / parallel system. A terminal SERIAL / XPARALLEL to which a method selection signal for selecting method switching control data and seven terminals are provided as a switching control signal supply pin.

The terminal used in serial communication is the terminal SERI
AL / XPARALLEL, 4 ports from terminal port 1 to terminal port 3.

The serial / parallel I / F circuit 1 has signals CS and S supplied from terminal ports 1 to 3 as at least three control lines required for serial communication.
CK and SI are used. Serial / parallel I / F circuit 1
Is the mode switching control data for setting the mode of the modules 1 to 4 from the supplied serial switching control data, and each of the switching switches SW1 to SW1 of the switching switch SW.
It is supplied to the terminal a side of SW4. In this mode setting device, for example, four change-over switches SW1 are provided in accordance with a system selection signal supplied via a terminal SERIAL / XPARALLEL of the LSI.
The mode switching control data is supplied to each of the modules 1 to 4 by interlocking with each other to switch SW4 to the terminal a side so as to fall.

In this way, when serial control is used, control bits corresponding to the number of modes can be assigned to each module and controlled by the serial / parallel I / F circuit 1 unless the communication length is limited. . According to this serial communication, a peripheral circuit for communication such as a microcomputer is required, but fine mode control can be realized.

Each module has an LSI terminal SERIAL / X
For example, four setting switches SW1 to SW4 are interlocked with each other so as to be tilted to the terminal a side in accordance with a system selection signal supplied via PARALLEL, and thereby setting data according to the application is supplied.

Further, in the case where the product specifications, for example, of the seven provided terminals which can be controlled by the six terminals other than the terminal SERIAL / XPARALLEL are simply configured, the LSI uses parallel mode setting. That is, the LSI generates the mode setting data from the six parallel switching control data supplied by using the logic circuit internally built in the decoding circuit 2. In this case, the serial switching control data supplied via the terminal ports 1 to 3 will be supplied as data for outputting the parallel switching control data.

The decoding circuit 2 supplies the outputs to the terminals b of the changeover switches SW1 to SW4 whose changeover operations are interlocked in the changeover switch SW.

However, in this case, since the LSI is selected based on 6 data, only 64 kinds of modes can be set at maximum. As described above, the LSI cannot perform all the module functions by selecting the 72 types of modes, but the peripheral circuit can be relatively small in scale, such as not using a communication circuit such as a microcomputer. Therefore, the load on the microcomputer can be reduced.

With the above-mentioned structure, it is possible to make an LSI in which the internal modules are common but the control method is different, and it is possible to easily use the LSI properly according to the user's purpose.

As a result, since the serial mode can be set as compared with the conventional LSI in which only the parallel mode is set, more detailed mode control can be performed.

In addition, the mode setting L of the serial method only is used.
By dividing the mode as compared with SI, control by a microcomputer with a small ROM capacity becomes possible.

Further, by sharing the terminal for serial data and the terminal for parallel data, the mode setting function can be realized with a smaller number of pins without increasing the number of pins.

Therefore, since only one type of LSI can set the serial / parallel mode,
It is possible to significantly reduce the development man-hours required to develop a plurality of types of LSIs and reduce costs.

[0031]

According to the mode setting device of the present invention,
By configuring, for example, an LSI or a circuit in which the internal modules are common but only the control method is different, it becomes possible to easily use the modules according to the application of the user.

As a result, the serial mode can be set as compared with the conventional circuit for setting the mode only for the parallel system, so that more detailed mode control can be performed.

Further, by dividing the mode as compared with the circuit for setting the mode only in the serial system, control by a microcomputer having a small ROM capacity becomes possible.

Furthermore, by sharing the terminal for serial data and the terminal for parallel data, the mode setting function can be realized with a smaller number of pins without increasing the number of pins.

Therefore, since the circuit can be set to the serial / parallel mode with only one type, the development man-hours required for the development of a plurality of types of LSIs can be greatly reduced and the cost can be reduced. be able to.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a mode setting device according to the present invention.

[Explanation of symbols]

 1 serial / parallel I / F circuit 2 decoder circuit SW, SW1 to SW4 changeover switch MOD1 to MOD4 module 1 to module 4

Claims (2)

[Claims] 1. Serial / parallel data conversion means for converting supplied serial switching control data into parallel switching control data; setting data generating means for generating a setting mode signal from the supplied switching control data; / A mode setting device having switching means for switching and selecting output signals from the parallel data converting means and the setting data generating means. 2. The mode setting device according to claim 1, wherein the switching means switches in conjunction with a switching selection signal indicating a serial system / parallel system supplied corresponding to a plurality of modules.