JPH0716434U - Programmable level translator - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a programmable level converter capable of performing a plurality of types of level conversion with one type of integrated circuit, improving the design efficiency of the integrated circuit, and achieving cost reduction. A level conversion block 33 composed of a first level conversion element 31 for converting a TTL level signal into a second voltage system signal and a second level conversion element 32 for converting a CMOS level signal into a second voltage system signal, The first level conversion element 31 is selected in response to the TTL level signal and C
The second level conversion element 32 corresponding to the MOS level signal
And a control block 36 for controlling the plurality of sets of selection blocks 34, 35 based on control data, and a control block 3 for selecting the selection blocks 34, 35.
6 has a data input interface 37 for registering control data.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to a first voltage system logic circuit (for example, a 5V system logic circuit) composed of an integrated circuit composed of a plurality of types of functional elements having different operation levels such as TTL-IC, CMOS-IC and ECL-IC. The present invention relates to a programmable level converter that functions as an interface with a second voltage system logic circuit (for example, a 3V system logic circuit) configured by an IC other than the first voltage system logic circuit.

[0002]

[Prior art]

 FIG. 2 shows a conventional example. In FIG. 2, 41 is a first voltage system logic circuit (5V system logic circuit) composed of, for example, TTL-IC and CMOS-IC, and 42 is a second voltage system composed of an IC other than the first voltage system logic circuit. System logic circuit (3 V system logic circuit; 12 V system logic circuit in some cases). Reference numerals 43 and 44 denote level converters (comprising integrated circuits) interposed between the signal input / output terminal of the first voltage system logic circuit 41 and the signal input / output terminal of the second voltage system logic circuit 42.

The level converter 43 is inserted and connected between the TTL system signal input / output terminal of the first voltage system logic circuit 41 and the signal input / output terminal of the second voltage system logic circuit 42, and the first voltage system signal To convert the TTL level signal in the above into a second voltage system signal. Further, the level converter 44 is connected between the CMOS system signal input / output terminal of the first voltage system logic circuit 41 and the signal input / output terminal of the second voltage system logic circuit 42 to connect the first voltage system signal The inside CMOS level signal is converted into the second voltage system signal.

In this way, the level converters 43 and 44 mediate the transfer of signals between the first voltage system logic circuit 41 and the second voltage system logic circuit 42, which have different operating power supply voltages and operating function elements. become.

[0005]

The level converters 43 and 44 require a plurality of types, for example, for TTL or CMOS, depending on the type of combination of signal levels to be converted. When designing vessels, there were many types, so the design efficiency was poor, the cost was high, and there was a disadvantage in parts procurement.

Therefore, an object of the present invention is to provide a programmable level converter capable of performing a plurality of types of level conversion with one type of integrated circuit, improving the design efficiency of the integrated circuit, and achieving cost reduction. That is.

[0007]

[Means for Solving the Problems]

 The programmable level converter of the present invention is composed of a plurality of types of first voltage system logic circuits composed of TTL-IC, CMOS-IC, ECL-IC, etc. and ICs other than this first voltage system logic circuit. The second voltage system logic circuit intervenes to convert a plurality of types of first voltage system signals such as TTL level signals, CMOS level signals and ECL level signals into second voltage system signals. , A level conversion block including a plurality of types of level conversion elements for converting a plurality of types of first voltage system signals into a second voltage system signal, respectively, and a plurality of types corresponding to the plurality of types of first voltage system signals. Selection block for selecting any one of the level conversion elements, the control block for controlling the selection block based on the control data, and the data for registering the control data in the control block. And an input interface.

[0008]

[Action]

 According to the configuration of this invention, by changing the control data to be registered, the plurality of types of first voltage system signals such as the TTL level signal, the CMOS level signal and the ECL level signal are level converted into the second voltage system signal. The operation can be switched automatically.

[0009]

【Example】

 FIG. 1 shows a block diagram of a programmable level converter according to an embodiment of the present invention. In FIG. 1, reference numeral 10 is a first voltage system logic circuit (5V system logic circuit) composed of, for example, TTL and CMOS-IC, and 20 is a second voltage system logic circuit composed of an IC other than the first voltage system logic circuit. It is a circuit (3V system logic circuit; it may be a 12V system logic circuit). Reference numeral 30 denotes a programmable level converter (comprising an integrated circuit) interposed between the signal input / output terminal of the first voltage system logic circuit 10 and the signal input / output terminal of the second voltage system logic circuit 20.

The programmable level converter 30 is provided between the TTL system signal input / output terminal and the CMOS system signal input / output terminal of the first voltage system logic circuit 10 and the signal input / output terminal of the second voltage system logic circuit 20. The TTL level signal included in the first voltage system signal is connected to the second voltage system signal and the CMOS level signal included in the first voltage system signal is converted into the second voltage system signal.

Here, the programmable level converter 30 will be specifically described. The programmable level converter 30 includes a first level conversion element 31 for converting a TTL level signal into a second voltage system signal and a second level conversion element 32 for converting a CMOS level signal into a second voltage system signal. And a selection block 34, 35 for selecting the first level conversion element 31 corresponding to the TTL level signal and selecting the second level conversion element 32 corresponding to the CMOS level signal. It has a plurality of sets, and has a control block 36 that controls the plurality of sets of selection blocks 34 and 35 based on control data, and a data input interface 37 that registers control data in the control block 36.

In the configuration described above, the first level conversion operation for converting the TTL level signal into the second voltage system signal by changing the control data registered in the control block 36 via the data input interface 37. The second level conversion operation for converting the CMOS level signal into the second voltage system signal can be switched. That is, when the control data is set so that the selection blocks 34 and 35 are switched to the side a, the first level conversion element 31 is in the operating state, and when the control data is set to be switched to the side b, the second level conversion element 31 is converted. The element 32 is activated.

Therefore, when the TTL system signal input / output terminal of the first voltage system logic circuit 10 is connected to the programmable level converter 30, the control data is set so that the selection blocks 34 and 35 are switched to the a side. When the CMOS signal input / output terminal of the first voltage system logic circuit 10 is connected to the programmable level converter 30, the control data is set so that the selection blocks 34, 35 are switched to the b side. That is, depending on whether the signal input / output terminal of the first voltage system logic circuit 10 connected to the programmable level converter 30 is the TTL system or the CMOS system, the selection blocks 34 and 35 are set to the a side or the b side, respectively. Set the control data by the program to switch. In this case, the selection blocks 34 and 35 can be independently switched for each input / output terminal connected to the input / output terminals of the first voltage system logic circuit 10 and the second voltage system logic circuit 20, respectively. .

According to this embodiment, when the control data registered in the control block 36 is changed by the data input interface 37, the first level conversion element 31 operates to change the TTL level signal to the second voltage system signal. The first level conversion operation for converting to the second level conversion operation for converting the CMOS level signal into the second voltage system signal by operating the second level conversion element 32 can be switched to one type of integrated circuit. It is possible to perform two types of level conversion by using the software, and it is not necessary to pay attention to the correspondence between the input / output terminals and the signal level in the circuit design. The cost can be reduced by increasing the design efficiency of the integrated circuit.

In the above embodiment, the programmable level converter 30 includes the TTL system signal input / output terminal and the CMOS system signal input / output terminal of the first voltage system logic circuit 10 and the second voltage system logic circuit 20. The TTL level signal in the first voltage system signal is converted into the second voltage system signal by being connected to the signal input / output terminal and the CMOS level signal in the first voltage system signal is converted into the second voltage system signal. However, the present invention is not limited to this, and a level conversion element for converting the ECL level signal into the second voltage system signal or converting the 12V system power supply voltage signal into the 3V system power supply voltage signal is illustrated. In addition to the configuration of FIG. 1, the number of switching circuits may be added to the selected block by adding the level conversion element.

[0016]

[Effect of device]

 According to the programmable level converter of the present invention, by changing the control data to be registered, a plurality of types of first voltage system signals such as TTL level signals, CMOS level signals and ECL level signals can be converted into second voltage system signals. The level conversion operation can be automatically switched, and multiple types of level conversion can be performed with one type of integrated circuit. In addition, pay attention to the correspondence between input / output terminals and signal levels in the circuit design. There is no need to pay, and the design efficiency of the integrated circuit can be improved and cost reduction can be achieved.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a programmable level converter according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional example.

[Explanation of symbols]

 10 first voltage system logic circuit 20 second voltage system logic circuit 30 programmable level converter 31 first level conversion element 32 second level conversion element 33 level conversion block 34 selection block 35 selection block 36 control block 37 data input interface

Claims (1)

[Scope of utility model registration request] 1. TTL-IC, CMOS-IC and E
A TTL level signal is provided between a plurality of types of first voltage system logic circuits composed of CL-IC and the like and a second voltage system logic circuit composed of ICs other than the first voltage system logic circuit. A programmable level converter for level-converting a plurality of types of first voltage system signals such as a CMOS level signal and an ECL level signal into a second voltage system signal, the plurality of types of first voltage system signals being a second voltage system signal. A level conversion block including a plurality of types of level conversion elements for converting into signals, and a selection block for selecting one of the plurality of types of level conversion elements corresponding to each of the plurality of types of first voltage system signals, A control block for controlling the selection block based on the control data; and a data input interface for registering the control data in the control block. Programmable level converter.