JPS5839050A - Integrated circuit - Google Patents

Abstract

PURPOSE:To enable to grasp the reliability of an integrated circuit by providing a simple selecting circuit and a decoder in the circuit, thereby discriminating the redundancy of a redundancy circuit from its exterior. CONSTITUTION:A redundancy circuit is checked by providing a circuit for examining how much the redundancy is retained on the same integrated circuit, thereby examining the redundancy and grasping the reliability of the chip. A circuit for examining the redundancy is composed of a simple decoder and a gate circuit. For example, the circuit has signal processors a1, a2, a3, b1, b2, b3,... majority decision circuits A1, A2, A3,... and decoder B, and these circuits are formed on the same silicon chip.

Description

[Detailed description of the invention] TECHNICAL FIELD This invention relates to integrated circuits.

Conventionally, when realizing a high magnification 1IliIc system, 2
I have thought of two methods. 1) increases the reliability of the parts that make up the system, and the other 1)? 1. V
Anticipate in advance that a part of the system will break down,
The circuit configuration has redundancy, so even if one part fails,
This is to prevent it from being seen as a failure from the outside.

A typical redundant circuit configuration utilizes the principle of majority voting shown in FIG.

In FIG. 1, @ 811 part g tag is the same circuit.

The same output signal from Al is input n% al*a2*a
, the output signal from A2 is input to the majority decision circuit of A2.
The signal is input to the circuit t bl t bs, and a single output is similarly obtained by majority vote. With such a circuit configuration, even if one of the a@tE12ta is out of order, a correct signal will be sent to the next stage circuit.

However, even if one of the al-eaz sag is out of order, the system appears to be operating normally from the outside, but the reliability of the system is
significantly lower than if everything was working properly. When al*IigeaB is a system based on printed circuit boards, the reliability of the system can be kept constant by periodically checking each a1 and every DaB.

However, even if the entire system is configured with redundancy in a large-scale integrated circuit such as one built on a single silicon substrate, if the degree of redundancy cannot be determined from the outside, it is difficult to judge the reliability of the chip. As a result, it becomes difficult to judge the reliability of the system.

The present invention examines how much redundancy remains in an integrated circuit from the outside.
A circuit is provided on the same conductive substrate, and the redundancy level t of the integrated circuit is checked using this judgment circuit to provide an integrated circuit for producing a highly reliable device.

In the present invention, conventionally, a redundant circuit is provided inside an integrated circuit.
By installing a circuit to check how much redundancy remains on the same integrated circuit, it is possible to check the redundancy and investigate the redundancy. The reliability of the chip was determined based on the reliability of the chip. It was. The circuit for checking redundancy t is:

It can be configured with a simple decoder and gate circuit.

Embodiments of the present invention are shown in FIGS. 2 and 3.

Figure 2 shows the signal processing circuit (al sag sag)*(
blt.

bll)m)"'Majority circuit A, ,A, ,A,...
. . , and decoder B, and the circuits of cn et al. are constructed on the same silicon chip. (a
It is assumed that the signal processing circuits l*aHtlkB)t(b,vJeb@)... each operate normally when 8EL1 (i=1 to 3) are at H level, and when i and 8EL are at L level. teeth.

Each output is fixed at H level or L level.

Also, when CK goes to H level, all 8EL1 goes to H level and performs normal operation, and when OK goes to L level, 10
If any one of 5ELi is selected n, now 8), and Ll is selected n9, the signal flow r is converted into an evolutionary signal.
t is AI-a 1 →A 2-e l).

It becomes A3 and a circuit check of % (al warning b11...) can be performed.

In the example shown in Figure 3, a selector that can select each signal processing circuit independently is provided on the same silicon chip, making it possible to check each signal processing circuit alone.

Figure 3 shows each signal processing block (atb#...)
The selector used in FIG. 2 is provided independently at (B1°B2.
(...) A selector C for selecting a selector is provided, but it is constructed on the same silicon chip along with a signal processing circuit and a majority decision circuit. The select signal line from selector C requires the number of blocks of the signal processing circuit,
These signals are input to AL)1-Al)i and then decoded into a binary coded signal t and converted into decimal (D(81~
1i) t-use. Furthermore, the signal line of 5l-8i is B
It becomes the select signal of the selector l-, Bi, and each signal processing block (aMsebMs=-・)? select. Mata.

The selection of the circuit within each signal processing block is performed by the signal ADDI*ADD2 GK similar to that shown in FIG. In the case of A, the CK terminal is set to H as in Figure 2.
level, the chip will be in a normal operating state.

FIG. 4 shows an example of the configuration of the signal processing block.

#! In Figure 4, s aHe au * all are signal processing circuits with the same structure, and each 8E-L i (i=
1 to 3) operate normally when they are at L level, and when they are at H level, their outputs are in a high impedance state.

At this time, the signal input to *Ii (t''=t~3) is.

A game with a tri-state output of Gi (1-1 to 3)
1- and output to 0i (1-1 to 3).

Also, in FIG. 4, 11. Input signal of I, ,I,!
Even if there are a plurality of Is, the same operation as described above can be performed.

By adopting the circuit configuration as shown in FIG. 3, FIG. 4, or FIG.

The present invention is based on one or more of the simple select circuits and decoders (
b) By providing the circuit inside the integrated circuit.

The degree of redundancy of redundant circuits can be determined from the outside, and the reliability of built-in circuits can be determined.

[Brief explanation of drawings]

The first (2) is a diagram showing a 3-to-l majority circuit.hMz diagram is 1
FIG. 3 is a diagram showing one embodiment of the present invention, and FIG. 4 is a diagram explaining in detail a or b of FIG. 3. lUII,,I,...Identical signal s from the previous stage
``11 'a□j t all・Old...Same signal processing circuit.

Claims (3)

[Claims] (1) In an integrated circuit in which redundancy is provided to the number of constituent elements of a required circuit on one semiconductor substrate, and the required circuit is configured with more elements than the minimum number of elements, the redundancy An FC integrated circuit characterized in that it is provided with a means for determining from the outside how much n remains. (2) The integrated circuit as recited in claim (1), characterized in that a circuit that can increase the reliability of the redundant circuit by +U by selecting the external terminal is constructed on the semiconductor substrate. (3) A binary-decimal decoder is constructed on the semiconductor substrate, and the reliability of the redundant circuit is t-! ! The integrated circuit according to claim (2), characterized in that it has a function of determining sJ.