JPS59229641A - Commumication control device - Google Patents

Abstract

PURPOSE:To access a circuit control word easily by a program and to improve the processing ability of a commumication control device by replacing a memory address by a circuit control number. CONSTITUTION:A program control part 1 sets up a range for replacing an address in a MODE register 4 and also sets a circuit control word number to be accessed in an ADRS register 6. An address comparator 5 compares an outputted memory address with the contents of the MODE register 4, and when the contents of the MODE register 4 are equal to the memory address or smaller than the memory address the contents of the memory address are replaced by the contents of the ADRS register 6 and the replaced memory address is sent to a memory 8 to access the objective circuit control word.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a communication control device having a memory storing line control words, and more specifically, to a communication control device having an improved method of accessing the line control word memory by a program.

Conventionally, in a configuration in which a line control word exists in the address space of a memory that stores a program that executes communication processing, it takes time to create a memory address for accessing the line control word memory. The drawback was that it was not possible to measure the improvement in processing capacity.

SUMMARY OF THE INVENTION An object of the present invention is to provide a communication control device that improves communication processing ability by easily generating addresses for accessing line control words existing in memory in a short time.

In order to achieve the above object, a communication control device according to the present invention is a communication control device having a memory storing a line control word, and a MOD that holds an address range of the line control word memory.
an E register, a comparator that compares the access request memory address issued from the program with the MODE register output, and determines whether or not the access request memory address is the line control word access request memory address; When the ADBS register holding the number and the comparator determine that it is a line control word access request memory address, a part of the line control word access request memory address is replaced with the line control word number, and the replacement address is and a selector for outputting the data to the memory.

According to the above configuration, the memory address of the line control word can be easily created, and the processing performance can be improved, so that the object of the present invention can be completely achieved.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a communication control device according to the present invention.

In the figure, 1 is a program control unit (PC), and 2 is a data bus line, which is composed of 8 bits.

3 is a Tedless bus line consisting of 16 pits. 4 is a register (M
ODE), 5 is MODE! 6 is a register (AI) R8) that holds the line control word number to be replaced with the memory address; 7 is the memory a selector that replaces the address and the contents of the ADR8 register;
8#'1 Memory (MEM) containing line control word (LCW) 9
).

FIG. 2 shows the structure of the line control word (LCW) located at the upper part of the memory address space of the memory 8.
~#127 indicates the line control word (LCW) number. It consists of one LCWti of 16-byte memory.

FIG. 3 shows the correspondence between the pit positions for replacing the memory address and the contents of the ADRS register 6 in the LCW configuration shown in FIG.
This indicates the pit position where the contents of the ODE register 4 and the memory address are compared.

The operation of the embodiment configured as described above will be explained as follows.

First, it is necessary to set in the MODE register 4 the range in which program control unit IFi addresses are to be replaced. Although FIG. 2 of this embodiment only shows the memory layout of 1ltLcW, the restriction words corresponding to the line that are accessed only by the program are 1. , CW is arranged in a memory address space with a lower number in the area where LCW is arranged, and this function is also effective when address conversion is performed for this area as well.

Program control unit 1 (PC)flLCW you want to access
Set the number in ADR8 register 6.

After that, the memory address in the LCW area, for example (F8
0F) Output is. The address comparison circuit 5 compares the output memory address (211 to 215) and the contents of the MODE register 4 (2° to 24).If the contents of the LMODE register 4 and the memory address are equal, or if the memory address is larger, the memory address is (24-210)
A.

The content of the DBS register 6 (20 to 26) is replaced and the memory address after the replacement is sent to the memory (MFiM) 8 to access the target LCW. To explain more specifically, for example, when accessing LCW #127, AD
When RS register 6Ilc (7F) tr is set and memory address (F80F) 16 is output, the memory address after address replacement becomes (FFFF) ts, and #127
The 16th byte in the LCW of is accessed.

As described in detail above, the present invention has the effect that by replacing a memory address with a line control word number, the line control word can be easily accessed by a program and the processing capacity of the communication control device can be improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the communication control device according to the invention; Fig. 2 is a diagram showing the structure of the line control word on the memory in Fig. 1; FIG. 1...Program control unit 2...Data bus line 3
... Address bus line 4 ... Register 5 ... Address comparison circuit 6 ... Register 7 ... Selector 8 ... Memory 9 ... Line control word Patent applicant NEC Corporation Agent Patent attorney Hisashi Inoro

Claims (1)

[Claims] A MOD that maintains the address range of the line control word memory in a communication control device that has a memory that stores the line control word.
an E register, a comparator that compares the access request memory address issued from the program with the MODE register output, and determines whether or not the access request memory address is the line control word access request memory address; When the ADR8 register holding the number and the comparator determine that it is a line control word access request memory address, a part of the line control word access request memory address is replaced with the line control word number, and the replacement address is A communication control device comprising: a selector for outputting the data to the memory.