JPH0555907A - Programmable logic circuit device - Google Patents

Abstract

PURPOSE:To realize the programmable logic circuit device provided with both a volatile memory and a nonvolatile memory as definition use memories. CONSTITUTION:The programmable logic circuit device is provided with a logic circuit section 4 specifying the relation of connection of internal logic elements depending on 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 a 1st definition memory 3 comprising a nonvolatile memory, a 2nd definition memory 2 comprising a volatile memory and a selection control means 6 loading selectively a definition data from either of the 1st and 2nd definition memories to the logic circuit section 4. Since two kinds of volatile memory and nonvolatile memory are provided as definition memories, the memory is selected properly in matching with the application of the user.

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 a connection relation of internal logic elements is specified according to definition data (configuration data) and a definition memory section for storing the definition data. And a desired logic circuit can be obtained by writing the definition data according to the purpose in the definition memory unit.
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. For example, when incorporated into a general-purpose device such as a so-called personal computer, it may be necessary to change the contents of the logic circuit according to the processing. In such a case, a programmable logic circuit device equipped with a volatile memory is required. Is appropriate. On the contrary, in the case of operating as only one logic circuit after being incorporated in the device, it is suitable to mount the non-volatile memory as the definition memory.
This is because, unlike the case of using a volatile memory, there is no need to write the contents of the definition memory each time the operation is started up.

[0003]

By the way, in a series of processes from product development to commercialization as a mass-produced product, there is a demand for applying the programmable logic circuit device used in the final prototype in the development process to the mass-produced product as it is. There is. However, in the past, this requirement could not be satisfied for the following reasons. In other words, in a prototype, since it involves trial and error, a programmable logic circuit device having a volatile memory is used together with an external PROM that gives definition data to the volatile memory, whereas in a mass-produced product after development is completed. This is because there is a demand for adopting a programmable logic circuit device having a non-volatile memory that does not require an external PROM in order to reduce the product size as much as possible. in this way,
When a programmable logic circuit device having a volatile memory is adopted in a prototype and a programmable logic circuit device having a nonvolatile memory is adopted in a mass-produced product, generally, the physical structures of both programmable logic circuit devices are different. Therefore, it was necessary to redesign despite the same circuit configuration. Further, when the programmable logic circuit device having a different physical structure is replaced in this way, the operation timing becomes different, and it is also necessary to adjust the timing of the entire device in which it is incorporated.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the definition memory section includes:
Selective definition data from a first definition memory composed of a non-volatile memory, a second definition memory composed of a volatile memory, or one of the first and second definition memories. And selection control means for loading to the logic circuit section.

[0005]

The selection control means selects either the first definition memory or the second definition memory, and the definition data is loaded from the selected definition memory to the logic circuit section.

[0006]

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, there are provided a logic circuit section 4 in which the connection relationship of internal logic elements is specified according to the definition data, and a definition memory section 7 for storing the definition data given to this logic circuit section 4. I have it.

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 section 7 comprises a volatile memory 2, a non-volatile memory 3 and selection control circuits 5 and 6. The volatile memory 2 is composed of, for example, SRAM,
The non-volatile memory 3 is composed of, for example, EPROM. The selection control circuit 5 is a circuit for selecting which of the volatile memory 2 and the non-volatile memory 3 to store the definition data given from the outside through the input terminal 8, and the selection control circuit 6 is volatile. This is a circuit that selects either the memory 2 or the non-volatile memory 3, reads the definition data from the selected memory, and loads it into the logic circuit unit 4. The selection control circuits 5 and 6 operate based on a selection signal provided from the outside through 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 in the left and right sides in FIG. 1, but the actual physical structure is such that these circuits intertwine with each other. It is located at.

Next, the method and operation of application of this embodiment will be described. When the programmable logic circuit device of this embodiment is used in a prototype device, the volatile memory 2 is used to store definition data. This is because it is expected that the contents of the definition data will be changed. In this case, it is mounted on a board in an applicable device together with an external PROM in which definition data is written. When the power is turned on, the selection control circuit 5 selects the volatile memory 2 by a control signal externally supplied via the terminal 9, and the definition data is supplied from the external PROM (not shown) via the terminal 8. Write to the volatile memory 2. After that, the selection control circuit 6 reads the definition data from the volatile memory 2, which is also selected according to the control signal, and loads it into the logic circuit unit 4. As a result, the logic circuit section 4 functions as a desired logic circuit according to the definition data. To change the contents of the logic circuit composed of the logic circuit unit 4, replace the current external PROM with a PROM storing definition data according to the changed contents on the board. Achieved by.

As a result of trial and error in the prototype, when the definition data of the programmable logic circuit device applied to the mass-produced product is determined, the definition data is written to the non-volatile memory 3 at the stage before being mounted on the product. That is,
A control signal for selecting the nonvolatile memory 3 is given to the selection control circuit 5, and the definition data is written from the terminal 8. Programmable logic circuit device 1 in which definition data is written
Is incorporated in the product as a desired logic circuit according to the definition data without an external PROM. During operation, the selection control circuit 6 externally gives a selection signal for selecting the nonvolatile memory 3 via the terminal 9.

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

[0013]

As described above, according to the programmable logic circuit device of the present invention, since there are two types of definition memory, a volatile memory and a non-volatile memory, it is possible to select them appropriately according to the user's application. You can In particular, in the process of developing devices equipped with programmable logic circuit devices, volatile memory is used as the definition memory in prototype devices, and in mass-produced products, the optimum definition data obtained in the development process is directly stored in non-volatile memory. Only by storing, a programmable logic circuit device that does not require an external PROM can be provided.

[Brief description of drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Programmable logic circuit device 2 ... Volatile memory 3 ... Nonvolatile memory 4 ... Logic circuit unit 5, 6 ... Selection control circuit 7 ... Definition memory unit

Claims (1)

[Claims] 1. A programmable logic circuit including a logic circuit section in which a connection relationship of internal logic elements is specified according to the definition data, and a definition memory section for storing the definition data given to the logic circuit section. In the device, the definition memory unit includes a first definition memory configured by a non-volatile memory, a second definition memory configured by a volatile memory, and a first definition memory and a second definition memory. A programmable logic circuit device, comprising: selection control means for selectively loading definition data from either one into the logic circuit section.