CN103916132B

CN103916132B - A kind of function switch circuit suitable for chip testing

Info

Publication number: CN103916132B
Application number: CN201410122629.3A
Authority: CN
Inventors: 李晓骏
Original assignee: Xian Unilc Semiconductors Co Ltd
Current assignee: Xian Unilc Semiconductors Co Ltd
Priority date: 2014-03-28
Filing date: 2014-03-28
Publication date: 2018-08-21
Anticipated expiration: 2034-03-28
Also published as: CN103916132A

Abstract

The present invention proposes a kind of new function switch circuit suitable for chip testing.The function switch circuit for being suitable for chip testing includes mainly testing weld pad, string turns and circuit, control circuit and n bit level conversion circuits；The control circuit turns to string and circuit controls so that 1 bit level signal of testing weld pad output is turned by string and circuit conversion is m parallel-by-bit signals, here m≤n, is most exported after the m bit levels conversion in n bit level conversion circuits afterwards.The present invention replaces traditional fuse circuit using testing weld pad, can prick testing weld pad by external probe and input different signals, only use 1 testing weld pad, just realize the function of n fuse circuits in the prior art.

Description

A kind of function switch circuit suitable for chip testing

Technical field

The present invention relates to a kind of function switch circuits suitable for chip testing.

Background technology

In the design and its manufacture of chip, fuse circuit is often used.The main function of fuse is：In chip production After the completion, it needs to switch over fuse according to the setting of test result or function, its switching mainly passes through laser pair Preset fuse is blown in chip, the change of circuit rigid connection is realized, to change the working condition or function of circuit.

Because of reasons such as the differences of working power, the output signal of fuse circuit can not be used directly to circuit.Fuse The signal of circuit needs just to export after handling by level shifting circuit to be used to other circuits.In general, each fuse is electric Road connects a bit level conversion circuit.As shown in Figure 1, for fuse circuit structure in the prior art, n fuse circuits meet n in figure Bit level conversion circuit is used cooperatively.

N fuse circuits itself need to occupy larger area, and cannot restore after being blown by laser, it is difficult in core It is reused in built-in testing or function setting operation, therefore overall cost is higher.

Invention content

In order to solve the problems, such as that traditional scheme overall cost is higher, the present invention proposes a kind of new to be suitable for chip testing Function switch circuit.

The basic solution of the present invention is as follows：

A kind of function switch circuit suitable for chip testing includes mainly testing weld pad, string turns and circuit, control circuit With n bit level conversion circuits；The control circuit turns to string and circuit controls so that 1 bit level of testing weld pad output Signal is turned by string and circuit conversion is m parallel-by-bit signals, here m≤n, most afterwards through the m bit levels in n bit level conversion circuits It is exported after conversion.

Based on above-mentioned basic scheme, the present invention also does following specific optimization：

Above-mentioned control circuit includes logic circuit, clock circuit and counting circuit, logic circuit is used to turn to string and circuit, Clock circuit and counting circuit send out control signal, and control clock circuit according to the count value that counting circuit returns and turn simultaneously to string Circuit sends out clock signal.

Above-mentioned string turns and circuit includes n-bit data line and corresponding n subelement, and one end of n subelement is as simultaneously Row signal output end, the other end are connect altogether as serial signal input terminal；Each subelement includes a pair of phase inverters and connects respectively Two metal-oxide-semiconductors of enable signal and clock signal.

Advantages of the present invention：

The present invention replaces traditional fuse circuit using testing weld pad, and testing weld pad input can be pricked by external probe Different signals only uses 1 testing weld pad, just realizes the function of n fuse circuits in the prior art.

1. although control circuit, string → and conversion circuit are increased, relative to n fuse circuits, increased circuit Area very little, and power consumption also very little.

2. being changed to 1 testing weld pad by n fuse circuits, the hard link of circuit is had no need to change, increases the spirit of circuit Activity.

3. the realization of testing weld pad is simpler in technique.

Description of the drawings

Fig. 1 is the schematic diagram of traditional scheme.

Fig. 2 is the schematic diagram of the embodiment of the present invention one.

Fig. 3 is the schematic diagram of the embodiment of the present invention two.

Fig. 4 is the structural schematic diagram of control circuit in the present invention.

Fig. 5 is the structural schematic diagram that string turns simultaneously circuit in the present invention.

Specific implementation mode

Embodiment one

As shown in Fig. 2, original n fuse circuit is changed to 1 bit test pad, string → and conversion circuit are connect（It is serial to turn simultaneously Row）.N parallel-by-bit signals are converted by string → and conversion circuit, 1 Bits Serial signal, n parallel-by-bits signal passes through n bit levels Conversion circuit, may be implemented the conversion under a variety of different level export give other circuits use.Correspondingly, needing to be arranged additional Control circuit to string → and conversion circuit control.

As shown in figure 4, The present invention gives a kind of basic structures of control circuit.Control circuit main function is control string → and conversion circuit working condition.It includes logic circuit, clock circuit and counting circuit, and logic circuit controls clock circuit And counting circuit.

Assuming that string here turns and only needs to be converted to m（M≤n, this circuit can be to the arbitrary positions less than or equal to n Circuit is converted）.Logic circuit sends out control signal to clock circuit and counting circuit, while also to string → and conversion circuit Send enable signal.Clock circuit and counting circuit prepare to start to work.Counting circuit sets count value as m.Logic electricity later Road control clock circuit to string → and conversion circuit send out clock signal, coincidence circuit starts counting up, when counting circuit meter Number is when reaching the value m of setting, sends out signal control clock circuit and stops continuing to send signal to string → and conversion circuit, counts simultaneously Number circuits issue logic circuit signal, and logic circuit is received and sent out to string → and conversion circuit after the signal that counting circuit is sent Control signal.

Logic circuit is made of simple digital circuit, is not just described in detail herein, as long as can realize similar Function.

It has been merely given as a kind of way of realization of control circuit herein, has been not limited to this in practice, as long as on capable of realizing The similar functions stated.

Fig. 5 give it is a kind of string → and conversion circuit specific example.The left side is 1 position datawire in figure, and the right is n digits According to line, while further including n subelement.Here subelement is simple 6 pipe（Metal-oxide-semiconductor）Unit, wherein in each phase inverter Including two metal-oxide-semiconductors, the grid of other two metal-oxide-semiconductor meets clock signal, such as clock signal C1 respectively（clock1）With it is enabled Signal EN.

Specific work process is as follows：Signal transmits from left to right.The enable signal EN sent by control circuit is first turned off son The metal-oxide-semiconductor of rightmost in unit, later as n bit clock c1, c2 ... cn arrive successively, in subelement leftmost metal-oxide-semiconductor according to Secondary opening pays attention to while can only have the metal-oxide-semiconductor on the left side in a seat unit to open（Here it is answered by the signal wire that control circuit is sent Should be n, respectively c1, c2 ... cn）, the serial signal on the left side exists successively in n subelement, after clock signal stops, The enable signal EN sent by control circuit first opens the metal-oxide-semiconductor of rightmost in subelement, n-bit data parallel output.

String of the present invention turns and circuit is not limited to foregoing circuit structure, and those skilled in the art can also use it He realizes any form of circuit of similar functions.

Embodiment two

As shown in figure 3, original n fuse circuit is changed to testing weld pad, connect 1 bit level conversion circuit, by signal convert to Then the level of setting exports n parallel-by-bit signals by string → and conversion circuit.Correspondingly, needing that additional control electricity is arranged Road to string → and conversion circuit control.

Control circuit and the specific example of string → and conversion circuit can refer to the realization of above-described embodiment one.

Claims

1. a kind of function switch circuit suitable for chip testing, it is characterised in that：Include mainly testing weld pad, string turns and electricity Road, control circuit and n bit level conversion circuits；The control circuit turns to string and circuit controls so that testing weld pad is defeated The 1 bit level signal gone out is turned by string and circuit conversion is m parallel-by-bit signals, here m≤n, most afterwards through n bit level conversion circuits In m bit levels conversion after export.

2. the function switch circuit according to claim 1 suitable for chip testing, it is characterised in that：The control circuit Including logic circuit, clock circuit and counting circuit, logic circuit is used to turn to string and circuit, clock circuit and counting circuit hair The count value for going out and controlling signal, and returned according to counting circuit controls clock circuit, and to string turn, simultaneously circuit sends out clock signal.

3. the function switch circuit according to claim 1 or 2 suitable for chip testing, it is characterised in that：The string turns And circuit includes n-bit data line and corresponding n subelement, one end of n subelement is another as parallel signal output end End is connect altogether as serial signal input terminal；Each subelement includes a pair of phase inverters and connects enable signal and clock signal respectively Two metal-oxide-semiconductors.