JPH0563551A - Programmable logic circuit device - Google Patents

Abstract

PURPOSE:To realize the programmable logic circuit device whose function is momentarily revised. CONSTITUTION:The programmable logic circuit device is provided with a logic circuit section 4 in which the connection relation of an internal logic element is specified in response to definition data and a definition memory section 7 storing the definition data given to the logic circuit section 4, and the definition memory section 7 is provided with two volatile memories 2, 3 and a selection control means 6 loading the definition data selectively to the logic circuit section 4 from any of the volatile memories 2, 3. Thus, since the two volatile memories are provided as the definition memory, the definition data loaded to the logic circuit section 4 are revised by having only to use the selection control means 6 to select any of the volatile memories 2, 3. That is, it is not required to rewrite the definition data in the case of function revision different from the device having had only one definition memory, and the function is revised momentarily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable logic circuit device such as a programmable logic device (PLD) or a field programmable gate array (FPGA).

[0002]

2. Description of the Related Art A programmable logic circuit device of this type includes a logic circuit section in which connection relationships and logic specifications of internal logic elements are specified according to definition data (configuration data), and a definition for storing definition data. And a definition memory unit, and by writing the definition data in the definition memory unit, a desired logic circuit corresponding to the definition data can be obtained. Such programmable logic circuit devices can be roughly classified into those using a non-volatile memory as the definition memory and those using a volatile memory, and these are appropriately selected according to the application.

When incorporated in a general-purpose device such as a so-called personal computer, it may be required to change the contents of the logic circuit according to the processing. In such a case, a programmable logic device equipped with a volatile memory is required. Circuitry is suitable. For example, by rewriting the data in the definition memory for a programmable logic circuit device incorporated in a personal computer, the programmable logic circuit device is used as a parallel interface at one time and as a serial interface at another time. It is possible.

[0004]

However, since it takes a certain amount of time to rewrite the data in the definition memory, the switching must be performed in a short time.
One function could not be realized by one programmable logic circuit device. For example, after incorporating the programmable logic circuit device into a certain board of a personal computer and making the programmable logic circuit device function as a board check circuit that checks the state of the entire board on which it is mounted before this operation, enter this operation. After that, for example, FD
In order to function as a C (floppy disk controller), it is necessary to change the contents of the definition data in a short time, which is difficult to realize.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the definition memory section includes:
Two or more sets of definition memories composed of volatile memory and selection control means for selectively loading definition data from any one set of the definition memories into the logic circuit section are provided. ..

[0006]

By storing different definition data in each of two or more sets of definition memories, the definition data to be loaded into the logic circuit section can be simply selected by the selection control means. Can be changed instantly. The contents of the definition memory other than the definition memory selected by the selection control means can be rewritten.

[0007]

1 is a block diagram showing the internal structure of a programmable logic circuit device according to an embodiment of the present invention.
Inside the programmable logic circuit device 1, a logic circuit unit 4 in which connection relations and logic specifications of internal logic elements are specified according to the definition data, and a definition memory for storing definition data given to the logic circuit unit 4 It has a section 7.

The logic circuit section 4 includes a large number of programmable unit blocks and programmable wiring elements for connecting these unit blocks to each other. Each unit block includes a plurality of logic gate circuits, flip-flop circuits, etc., and these connections are programmable by definition data.

The definition memory unit 7 includes volatile memories 2 and 3 and selection control circuits 5 and 6. The volatile memories 2 and 3 are composed of, for example, SRAM. The selection control circuit 5 is a circuit for selecting which of the volatile memories 2 and 3 is to store definition data externally applied via the input terminal 8, and the selection control circuit 6
Is a circuit that selects either the volatile memory 2 or 3 and reads the definition data from the selected memory and loads it into the logic circuit unit 4. Selection control circuits 5 and 6
Operates based on a selection signal provided from the outside via the input terminal 9.

For the sake of simplicity, the layout of the logic circuit section 4 and the definition memory section 7 is clearly separated on the left and right sides in FIG. 1, but the actual physical structure, that is, the layout, is such that these circuits are mutually It is arranged intricately.

Next, the operation when this embodiment is applied to a personal computer (personal computer) will be described. Here, a case is considered in which the programmable logic circuit device of the present embodiment is made to function as an FDC at one time and as a board check circuit at another time.

When the power supply of a personal computer (not shown) is turned on, a selection signal for connecting the selection control circuit 5 to the volatile memory 2 side receives a CPU 10 of the personal computer via an input terminal 9.
Given by. Subsequently, definition data for the programmable logic circuit device to function as a board check circuit is supplied from the CPU 10 to the input terminal 8 and stored in the volatile memory 2. As a result, the selection control circuit 6
If the volatile memory 2 is selected and the volatile memory 2 is enabled, this programmable logic circuit device becomes a board check circuit, and before the personal computer starts its original operation,
Check if the board on which you are mounted is normal. How the board check circuit is specifically configured is not so important here. For the definition, select an appropriate one from various conventionally known circuits and make it the same circuit configuration. Just specify the data.

When the writing of the definition data as the board check circuit is completed, the selection control circuit 5 is separated from the volatile memory 2 by the selection signal and connected to the volatile memory 3. Then, the CPU 1 sends definition data for causing the programmable logic circuit device to function as the FDC.
It is read from 0 and written in the volatile memory 3. This write operation is executed and completed while the volatile memory 2 is selected by the selection control circuit 6 and the programmable logic circuit device is operating as a board check circuit. Therefore, when the personal computer enters this operation, the selection control circuit 6
If the volatile memory 3 is enabled by switching to the volatile memory 3 side, it can immediately function as the FDC.

In this embodiment, after functioning as a board check circuit, it functions as an FDC. However, if it is desired to function as another circuit if necessary, it may be operated during FDC operation. If new definition data is written in the volatile memory 2 in which the definition data as the board check circuit is written, the selection control circuit 6 is simply switched to the volatile memory 2 side after the operation as the FDC is completed. , Can be immediately operated as a circuit having a new function. Similarly, if one of the volatile memories is selected by the selection control circuit 6 and the definition data corresponding to the next required function is written in the other volatile memory, the volatile memory is always written in the volatile memory. Writing time can be substantially saved.

In this embodiment, two sets of volatile memories are provided as definition memories, but the present invention does not prevent provision of three or more sets of volatile memories.

In this embodiment, the selection control circuit 5 is built in the programmable logic circuit device 1, but this circuit may be externally attached.

Further, in this embodiment, the definition data is C
Although it is given from PU, it may be given directly from ROM or the like.

[0018]

As described above, according to the programmable logic circuit device of the present invention, since the definition memory has two or more sets of volatile memories, the selection control means switches the selection of the definition memory. The definition data to be loaded into the logic circuit section can be changed only by itself. That is,
Unlike the conventional device having only one definition memory, it is not necessary to rewrite the definition data when changing the function, and the function can be changed instantaneously.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

[Explanation of symbols]

 1 ... Programmable logic circuit device 2, 3 ... Volatile memory 4 ... Logic circuit section 5, 6 ... Selection control circuit 7 ... Definition memory section

Claims (1)

[Claims] 1. A logic circuit section in which connection relations and logical specifications of internal logic elements are specified according to definition data, and a definition memory section for storing the definition data given to this logic circuit section. In the programmable logic circuit device, the definition memory unit selectively defines definition data from two or more sets of definition memories configured by a volatile memory and one of the definition memories. A programmable logic circuit device comprising: a selection control unit that loads the unit.