JP2001308278A - Semiconductor integrated circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit for which connection testing between each functional block can be carried out easily without activat ing a plurality of functional blocks simultaneously. SOLUTION: If a selected signal TEST is in an active state, a loopback circuit 14 forms a wiring path of a wiring 13a to a wiring 14a and then to a wiring 13d. If an output signal of a first functional block and an input signal of the first functional block are at the same level, it can be determined that the connection of this wiring path is normal. If the selected signal TEST is in a non-active state, each wiring 13c, 13d is interconnected by means of the loopback circuit 14, and the wiring 14a and the wiring 13d are separated. Then, by measuring an input signal of a block 15 and an output signal of the block 15 in a condition activating a second functional block 12 by using a test program, it can be determined that the connection of the wiring path in the block 15 is normal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit such as an ASIC in which a plurality of functional blocks are integrated on a single chip, and more particularly to a semiconductor integrated circuit capable of easily performing a connection test between functional blocks.

[0002]

2. Description of the Related Art ASIC (Application Specific IC)
Such a semiconductor integrated circuit is a circuit in which a plurality of functional blocks such as a communication circuit and a data processing circuit centering on a CPU core are integrated on one chip. In order to perform an operation test of each functional block of such a semiconductor integrated circuit,
Test terminals connected in parallel with the input or output of each functional block are provided, and input / output of each functional block is inspected via these test terminals.

When testing the connection state of the signal transmission wiring connecting the functional blocks, the functional blocks are simultaneously operated to determine whether or not the mutual operation of the functional blocks is performed normally. Inspection.

[0004]

However, in such a connection test method between functional blocks of a semiconductor integrated circuit, it is necessary to specially create a program for simultaneously operating a plurality of functional blocks.

[0005] The functional block is an IP (Information).
Provider) is often incorporated as a core. This I
The test program for the P core is supplied to the manufacturing side from each IP pendor together with the circuit. Furthermore, some IP pendants do not disclose the internal information of the function block.
For these reasons, it has been very difficult to create a program for performing a connection test between each functional block.

In view of the above, the present invention has been made in view of the above-mentioned conventional problems, and provides a semiconductor integrated circuit capable of easily performing a connection test between functional blocks without simultaneously operating a plurality of functional blocks. The purpose is to provide.

[0007]

In order to solve the above-mentioned problems, the present invention provides first and second functional blocks, and the first and second functional blocks.
And a signal transmission line for connecting between the second function blocks, wherein a signal transmitted from the second function block to the first function block via the signal transmission line is blocked. In addition, a loopback circuit is provided for returning the signal output from the first function block to the first function block via the signal transmission wiring and inputting the signal instead of the cut-off signal.

According to the present invention, the loop-back circuit cuts off the signal transmitted from the second functional block to the first functional block via the signal transmission wiring, and replaces the signal. The signal output from the first functional block is returned to the first functional block via the signal transmission wiring and input. In this state, by comparing the signal input to the first functional block with the output signal, the connection state of the wiring path to which the signal is transmitted can be determined. In addition, the second
When the signal from the function block is not interrupted, the connection state of the wiring path near the second function block including the loopback circuit can be determined by confirming the function of the second function block through the loopback circuit. it can. As a result, it is possible to determine the connection state of the entire signal transmission wiring between the first and second functional blocks.

It should be noted that the present invention is not limited to only one set of first and second functional blocks among a large number of functional blocks on a semiconductor integrated circuit, but a plurality of sets of first and second functional blocks.
The present invention can be applied to functional blocks, and a plurality of sets of first and second functional blocks may have a mutually overlapping relationship.

According to another aspect of the present invention, there is provided a semiconductor integrated circuit having at least first and second functional blocks and a signal transmission line connecting between the first and second functional blocks. And the first signal is replaced by the first signal.
The second from the functional block via the signal transmission wiring
A through circuit is provided for making a signal transmitted to the functional block an output of the second functional block.

According to the present invention, the through circuit cuts off the signal output from the second function block and replaces the cut-off signal with the signal from the first function block via the signal transmission wiring. Thus, the signal transmitted to the second functional block is used as the output of the second functional block. In this state, by comparing the signal output from the first functional block with the output of the second functional block, it is possible to determine the connection state of the wiring path to which this signal is transmitted.
If the signal is not cut off by the through circuit, the connection state of the wiring path near the second functional block including the through circuit can be determined by testing the function of the second functional block through the through circuit. .
As a result, it is possible to determine the connection state of the entire signal transmission wiring between the first and second functional blocks.

It should be noted that the present invention is not limited to only one set of first and second functional blocks among a large number of functional blocks on a semiconductor integrated circuit, but a plurality of sets of first and second functional blocks.
The present invention can be applied to functional blocks, and a plurality of sets of first and second functional blocks may have a mutually overlapping relationship.

As described above, in the present invention, it is not necessary to specially create a program for a connection test unlike the related art. Further, since the present invention does not hinder the operation test of each functional block, even if the present invention is applied,
There is no need to modify the function block test program supplied from the P vendor or the like.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing a first embodiment of the semiconductor integrated circuit of the present invention. FIG.
As shown in FIG. 1, the semiconductor integrated circuit according to the present embodiment is integrated on one chip, and includes a first functional block 11,
Second function block 12, first and second function blocks 1
A signal transmission line 13 connecting between the signal transmission lines 1 and 12 and a loopback circuit 14 provided on the signal transmission line 13 are provided.

The signal transmission wiring 13 includes wirings 13a, 13b, 13c and 13d for transmitting signals between the first function block 11 and the second function block 12. Each wiring 13
A loopback circuit 14 is inserted between c and 13d, and a wiring 14a branched from between the wirings 13a and 13b is connected to the loopback circuit 14.

In such a configuration, during a normal operation, the select signal TEST applied to the loopback circuit 14 is set to an inactive state. In response to the select signal TEST in the inactive state, the loopback circuit 14 interconnects the wirings 13c and 13d and disconnects the wiring 14a from each of the wirings 13c and 13d. In this state, the signal transmission from the first function block 11 to the second function block 12
13b, and transmission of a signal from the second functional block 12 to the first functional block 11 can be performed through each of the wirings 13c and 13d.

Next, the first and second functional blocks 11, 1
A procedure for testing the connection state of the signal transmission wiring 13 between the two will be described.

First, the select signal TEST is activated. In response, the loopback circuit 14
While separating between the wirings 13c and 13d, the wiring 14
a is connected to the wiring 13d. By the disconnection between the wirings 13c and 13d, transmission of a signal from the second function block 12 to the first function block 11 is cut off. Also, wiring 1
4a connected to the wiring 13d, the wiring 13a →
A wiring path from the wiring 14a to the wiring 13d is formed, and a signal output from the first function block 11 is returned to the first function block 11 and input through the wiring path.

Here, the output of the first functional block 11 is a signal A, and the input of the first functional block 11 is a signal A. These signals A and O are compared, and as a result, if the two signals A and O are at the same level, it can be determined that the connection of the wiring path of the wiring 13a → the wiring 14a → the wiring 13d is normal. If the signals A and O are not at the same level, it can be determined that the connection of the wiring path is abnormal. To compare the two signals A and O, a test program for this comparison is executed in the first functional block 11 or test terminals connected in parallel to the input and output of the first functional block 11 are provided. What is necessary is just to compare the two signals A and O via the test terminal.

Next, the select signal TEST is made inactive. In this case, as described above, the wirings 13c and 13d are interconnected by the loopback circuit 14, and the wiring 14a is separated from the wiring 13d.

Here, the input of the second functional block 12 is defined as a signal A, and the output of the second functional block 12 is defined as a signal C. The input of the block 15 including the second functional block 12 and the loopback circuit 14 is defined as a signal A ′, and the output of the block 15 is defined as a signal C ′. If the connection of the wiring path in the block 15 is normal, the logic levels of the signals c and c ′ match, and the logic levels of the signals a and b ′ match. Therefore, it is determined whether or not the operation of the second function block 12 is normal by measuring the signals A ′ and C ′ of the block 15 while the second function block 12 is operated by the test program. If this operation is normal, it can be further determined that the connection of the wiring path in the block 15 is normal. Also, the second
If it is determined that the operation of the function block 12 is abnormal,
There is a possibility that an abnormality has occurred in the connection of the wiring path in the block 15.

Thus, the wiring 13a → the wiring 14a → the wiring 1
If it is clear that the connection of the wiring path 3d is normal and that the connection of the wiring path in the block 15 is normal, it can be said that the connection of the entire signal transmission wiring 13 is normal. In such a test, there is no need to simultaneously operate the first and second functional blocks 11 and 12, unlike the conventional case, and it is not necessary to specially create a program for the connection test as in the conventional case.

In this embodiment, one set of the first and second sets is used.
Although the functional blocks are illustrated, the present invention is not limited to this. The present invention can be applied to a plurality of sets of first and second functional blocks, and a plurality of sets of first and second sets.
The functional blocks may have a mutually overlapping relationship.

FIG. 2 is a block diagram showing a second embodiment of the semiconductor integrated circuit according to the present invention. The semiconductor integrated circuit according to the present embodiment includes a first function block 21 and a second function block 2.
2, a signal transmission wiring 23 connecting the first and second functional blocks 21 and 22 and a through circuit 24 provided in the signal transmission wiring 23.

The signal transmission wiring 23 is composed of the respective wirings 23a, 23a
3b, 23c and 23d. Each wiring 23c, 23d
A through circuit 24 is inserted between the wirings 23 a and 23.
The wiring 24 a branched from the line b is connected to the through circuit 24.

In such a configuration, during normal operation, the select signal TE applied to the through circuit 24 is
ST is made inactive. In response, the through circuit 24 interconnects the wirings 23c and 23d and disconnects the wiring 24a from both of the wirings 23c and 23d. In this state, a signal can be transmitted from the first function block 21 to the second function block 22 through the wirings 23a and 23b, and the second function block 2
2, signals can be transmitted through the wirings 23c and 23d.

Next, a procedure for testing the connection state of the signal transmission wiring 23 will be described.

First, the select signal TEST is activated. In response, the through circuit 24 disconnects the wirings 23c and 23d and connects the wiring 24a to the wiring 23d. The disconnection between the wirings 23c and 23d interrupts the output of the signal from the second functional block 22. Further, by connecting the wiring 24a to the wiring 23d, a wiring path of the wiring 23a → the wiring 24a → the wiring 23d is formed, and a signal output from the first functional block 21 is transmitted through this wiring path.

Here, the output of the first functional block 21 is defined as a signal F, and the output of the block 25 including the second functional block 22 and the through circuit 24 is defined as a signal Q '. These signal powers are compared, and as a result, both signal powers are compared.
If the ク ′ is the same level, the wiring 23a → the wiring 24a →
It can be determined that the connection of the wiring route of the wiring 23d is normal. If the two signals are not at the same level, it can be determined that the connection of this wiring path is abnormal.

Next, the select signal TEST is made inactive. In this case, as described above, the wirings 23c and 23d are interconnected by the through circuit 24 and the wiring 24a and the wiring 23d are separated.

Here, the input of the second function block 22 is defined as a signal G, and the output of the second function block 22 is defined as a signal G. In addition, the input of the block 25 is defined as a signal 、, and the output of the block 25 is defined as a signal 'as described above. If the connection of the wiring path in the block 25 is normal, the logic levels of the signals K and K ′ match, and the logic levels of the signals K and K ′ match. Therefore, the second function block 22
Block 2 in a state where is operated by the test program
By measuring each of the signals' ′ and の ′, it is possible to determine whether the operation of the second function block 22 is normal or not.
It can be determined that the connection of the wiring path in the inside is normal. If it is determined that the operation of the second function block 22 is abnormal, there is a possibility that an abnormality has occurred in the connection of the wiring path in the block 25.

Thus, the wiring 23a → the wiring 24a → the wiring 2
If it is clear that the connection of the wiring path of the signal 3d is normal and that the connection of the wiring path in the block 25 is normal, it is determined that the connection of the entire signal transmission wiring 23 is normal. Can be. Moreover, unlike the related art, there is no need to operate the first and second functional blocks 21 and 22 simultaneously, and it is not necessary to specially create a program for a connection test.

In this embodiment, a set of the first and second sets
Although the functional blocks are illustrated, the present invention is not limited to this. The present invention can be applied to a plurality of sets of first and second functional blocks, and a plurality of sets of first and second sets.
The functional blocks may have a mutually overlapping relationship.

FIG. 3 is a block diagram showing a third embodiment of the semiconductor integrated circuit according to the present invention. The semiconductor integrated circuit according to the present embodiment includes a first function block 31 and a second function block 3.
2, a signal transmission line 33 connecting between the first and second functional blocks 31 and 32, and a loopback circuit 34 and a through circuit 35 provided in the signal transmission line 33.

The signal transmission wiring 33 is composed of each of the wirings 33a, 33
3b, 33c, 33d, 33e, and 33f. A loop-back circuit 34 is inserted between the wirings 33c and 33d, and a wiring 34a branched from the wirings 33a and 33b is connected to the loop-back circuit 34. In addition, each wiring 3
A through circuit 35 is inserted between 3e and 33f, and a wiring 35a branched from each of the wirings 33a and 33b is connected to the through circuit 3.
5 is connected.

In such a configuration, during a normal operation, the select signal TEST is set to an inactive state.
In response, the loopback circuit 34
The wirings c and 33d are interconnected, and the wiring 34a is cut off from each of the wirings 33c and 33d. The through circuit 35 interconnects the wirings 33e and 33f and disconnects the wiring 35a from both of the wirings 33e and 33f. In this state, signals can be transmitted and received between the first and second functional blocks 31 and 32, and signals can be transmitted from the second functional block 32 through the wirings 33e and 33f.

Next, a procedure for testing the connection state of the signal transmission wiring 33 will be described. First, the select signal TE
ST is set to the active state. In response, the loopback circuit 34 disconnects the wirings 33c and 33d, and connects the wiring 34a to the wiring 33d. As a result, transmission of signals from the second function block 32 to the first function block 31 is cut off, and a wiring path of the wiring 33a → the wiring 34a → the wiring 33d is formed. Are output to the first functional block 31 and input. At this time, the signal output from the first functional block 31 and the signal input to the first functional block 31 are compared.
It can be determined that the connection of the wiring route of a → the wiring 34a → the wiring 33d is normal.

The select signal TE in the active state
In response to ST, the through circuit 35 is connected to each of the wirings 33e and 33e.
f, and the wiring 35a is connected to the wiring 33f. Thereby, the output of the signal from the second functional block 32 is cut off, and the wiring 33a → the wiring 35a
→ A wiring path of the wiring 33f is formed, and a signal output from the first functional block 31 is transmitted through this wiring path. At this time, the signal output from the first functional block 31 is compared with the signal output from the block 36 including the second functional block 32 and the through circuit 35, and both signals are output at the same level. Then, wiring 3
It can be determined that the connection of the wiring route of 3a → wire 35a → wire 33f is normal.

Next, the select signal TEST is made inactive. In this case, as described above, the wirings 33c and 33d are interconnected by the loopback circuit 34, and the wiring 34a and the wiring 33d are disconnected. Further, each wiring 33e, 33 is provided by the through circuit 35.
f are interconnected, and the wiring 35a and the wiring 33f are disconnected.

Here, the input of the second functional block 32 is used as a signal, and each output of the second functional block 32 is used as a signal.
Data. Further, the input of the block 36 is defined as a signal
The output of the block 36 is referred to as each signal ','. If the connection of the wiring route in the block 36 is normal, each signal
, The logic levels of the signals S and S 'match, and the logic levels of the signals S and T' match. Therefore, by measuring each signal S ′, T ′, and S ′ of the block 36 while the second function block 32 is operated by the test program, it is determined whether the operation of the second function block 32 is normal. If it is determined that this operation is normal, it can be further determined that the connection of the wiring path in the block 36 is normal.

Thus, the wiring 33a → the wiring 34a → the wiring 3
If it is clear that the connection of the wiring path of 3d and the wiring path of the wiring 33a → the wiring 35a → the wiring 33f is normal and that the connection of the wiring path in the block 36 is normal, the entire signal transmission wiring 33 is provided. Can be determined to be normal.

In this embodiment, one set of the first and second sets
Although the functional blocks are illustrated, the present invention is not limited to this. The present invention can be applied to a plurality of sets of first and second functional blocks, and a plurality of sets of first and second sets.
The functional blocks may have a mutually overlapping relationship.

Further, by treating the signal output from the block 36 in the same manner as the signal of the first functional block 31,
If this signal is input to a loop-back circuit or a through circuit of a subsequent functional block (not shown), a connection test between the functional blocks can be performed in a wide range and easily.

Further, the same signal output from the first functional block 31 is transmitted to the loopback circuit 34 and the through circuit 3.
5, the signals different from each other may be input to each of the circuits 34 and 35 so that the connection between the two wiring paths may be individually tested.

If the number of wires increases, the smaller of the number of wires on the input side and the number of wires on the output side is appropriately branched, and the number of wires is adjusted. The loop-back circuit and the through circuit are configured by appropriately combining the wirings on the output side and the output side.

Further, in the case of a circuit configuration in which there is no equivalent to the signal output from the first functional block 31, even if a test terminal is provided outside the semiconductor integrated circuit and the signal is supplied through this test terminal, good. Similarly, when there is no equivalent to the first functional block 31 capable of observing the signal cell, a test terminal may be provided outside the semiconductor integrated circuit, and the signal cell may be observed through the test terminal.

[0047]

As described above, according to the present invention, it is not necessary to create a program for simultaneously operating a plurality of function blocks without operating a plurality of function blocks at the same time. A connection test between functional blocks can be easily performed. Further, by combining the two inventions described in the first and second aspects, a connection test between the functional blocks can be performed regardless of the configuration of the semiconductor integrated circuit.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a semiconductor integrated circuit of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the semiconductor integrated circuit of the present invention.

FIG. 3 is a block diagram showing a third embodiment of the semiconductor integrated circuit of the present invention.

[Explanation of symbols]

 11, 21, 31 First functional block 12, 22, 32 Second functional block 13, 23, 33 Wiring for signal transmission 14, 34 Loopback circuit 24, 35 Through circuit

Claims (2)

[Claims] A first and second functional block;
And a signal transmission line for connecting between the second function blocks, wherein a signal transmitted from the second function block to the first function block via the signal transmission line is blocked. And, in place of this blocked signal, the first
A semiconductor integrated circuit, comprising: a loopback circuit that returns a signal output from a functional block to the first functional block via the signal transmission wiring and inputs the signal to the first functional block. 2. The first and second functional blocks and the first and second functional blocks.
And a signal transmission line for connecting between the second functional blocks, wherein the signal output from the second functional block is interrupted, and the first function is substituted for the interrupted signal. A semiconductor integrated circuit, comprising: a through circuit that outputs a signal transmitted from a block to the second functional block via the signal transmission wiring to the second functional block.