JPH0344961A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To conduct the test outputs separately block by block to the outside by a method wherein a selector conducts the test outputs from function blocks through a test output pin according to the selection signals inputted from a selection signal input pin. CONSTITUTION:On a semiconductor chip 1, N-pieces of function blocks 21-2n are arranged and their test outputs are given to a selector 4. Selection signals are given to the selector 4 through selection signal input pin 5. The selector 4 selects one of the test outputs from the function blocks according to the selection signal and outputs that. The output of the selector 4 is given to a test output pin 3 and the test output of one of the function blocks is took out from the pin 3 to the outside. Thus, the test outputs of the function blocks can be conducted to the outside separately block by block with a few number of pins.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor integrated circuit device in which a plurality of functional blocks are mounted on a semiconductor chip.

[Prior Art] For example, there are various semiconductor integrated circuit devices such as microcomputers and semiconductor memories in which a plurality of functional blocks are provided on one semiconductor chip. In such a semiconductor integrated circuit device, there are cases where it is desired to verify the test output of each functional block.

FIG. 2 is a block diagram showing a conventional semiconductor integrated circuit device that can meet the above requirements.

In the figure, nl'II functional blocks 21, 22, 23 . ...2n is provided. These functional blocks 21, 22, 23. ...2
The test outputs of n are respectively connected to test output pins 31.3
2.33. ... taken out to the outside via 3n. Therefore, in a conventional semiconductor integrated circuit device, test output pins are required in correspondence with the number of functional blocks.

[Problems to be Solved by the Invention] Conventional semiconductor integrated circuit devices are configured as described above, so if you want to verify the test output of each functional block individually, you need a test output bin for each functional block. Therefore, there was a problem that the number of bins increased.

This invention was made to solve the above-mentioned problems, and aims to provide a semiconductor integrated circuit device in which the test outputs of each functional block can be output to the outside with an extremely small number of bins. purpose.

[Means for Solving the Problems] A semiconductor integrated circuit device according to the present invention is a semiconductor integrated circuit device in which a plurality of functional blocks are mounted on a semiconductor chip. A selection signal input bin that inputs a selection signal, a selector that receives test output from multiple functional blocks and selects and outputs the test output of one of the functional blocks according to the selection signal, and outputs the output of the selector to the outside. at least one test output pin for outputting.

[Operation] In this invention, the test output of each functional block is given to a selector, and the test output of any one functional block is selected by this selector. The output of the selector is taken out via at least one test output pin. The selector selects a test output according to a selection signal input from a selection signal input bin.

Therefore, in the present invention, it is only necessary to provide a selection signal input bin and a test output pin for each functional block. The number of bins can be reduced.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, n functional blocks 21, 22, 23 . ...2n is provided.

The test output of each functional block is given to the selector 4. A selection signal is applied to this selector 4 via a selection signal input bin 5 . The selector 4 selects and outputs the test output of any one of the test outputs from each functional block in response to this selection signal. The output of the selector 4 is applied to a test output pin 3 (one pin is provided when the test output for one functional block is 1 bit, and n pins are provided when the test output is n bits). Therefore, the test output of any one functional block is taken out from this test output pin 3 to the outside.

In the above configuration, consider a case where the number of functional blocks is, for example, eight.

In the conventional semiconductor integrated circuit device shown in FIG. 2, test output pins (8×n if the test output is n bits) are required for eight functional blocks. In contrast, in the embodiment shown in FIG. 1, there are three selection signal input bins 5 for inputting 3-bit selection signals;
It is sufficient to provide a test output pin 3 for one functional block. Therefore, the number of bins is significantly reduced compared to the conventional semiconductor integrated circuit device shown in FIG. The effect of reducing the number of bins increases as the number of functional blocks increases.

[Effects of the Invention] As described above, according to the present invention, the selector selects the test output from each functional block in accordance with the selection signal input from the selection signal input bin, and selects at least one test output for one functional block. Since the test outputs of each functional block are outputted to the outside through the test output pins, the test outputs of each functional block can be outputted to the outside with an extremely small number of bins compared to conventional semiconductor integrated circuit devices.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a block diagram showing a conventional semiconductor integrated circuit device. In the figure, 1 is a semiconductor chip, 21 to 2n are functional blocks, 3 is a test output pin, 4 is a selector, and 5 is a selection signal input bin.

Claims (1)

[Scope of Claims] A semiconductor integrated circuit device having a plurality of functional blocks mounted on a semiconductor chip, comprising: a selection signal input pin for inputting a selection signal for selecting one of the functional blocks; a selector that receives test outputs from the functional blocks and selects and outputs the test output of any one functional block according to the selection signal; and at least one test for outputting the output of the selector to the outside. A semiconductor integrated circuit device equipped with an output pin.