JPH04326445A - Control register write device - Google Patents

Abstract

PURPOSE:To reduce the load of software and to shorten write processing time in the register write device of a control register which can write one piece or more than two pieces of control data at once. CONSTITUTION:One or more than two bit groups which are written by a write permission signal at every control data and which are controlled are provided for the control register into which a control data string can be written at once in a control register part 12. A write control part 11 sets a write signal into the corresponding and controlled bit group to be the write permission signal when control data is a value becoming the object of write permission at the time of writing one piece or more than two pieces of control data, and sets the write signal into the corresponding and controlled bit group to be a write prohibition signal when the value of control data is beyond the object of write permission. Thus, only the write permission object of control data in the control data string are written into the corresponding and controlled bit group in the control register part 12.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control register writing device, and more particularly to a control register writing device capable of writing one or more pieces of control data at once.

[0002] In recent years, integrated circuits (ICs) and large-scale integrated circuits (LSIs) have come to be installed in all kinds of products and machines to control them, and the functions to be controlled have become more diverse and processing times have become shorter. Furthermore, ease of use of the hardware from the viewpoint of IC and LSI software is also required. Therefore, in order to shorten the control processing time of ICs and LSIs and improve the operability of hardware from a software perspective, it is necessary to shorten the writing processing time of control registers and reduce the software load. be done.

0003

2. Description of the Related Art FIGS. 5A and 5B are block diagrams of an example of a conventional control register writing device. FIG. 5(B) is a specific example of the control register of FIG. 5(A). In the same figure, 1
is a control register consisting of a control bit group 11 to 1n. 2 is a central processing unit (CPU), 3 is a memory, and these are connected together with the control register 1 by a bidirectional bus. The control register 1 has bit groups 11 to 1 controlled by the control data of each of the n control objects by the CPU 2.
The configuration is such that the data is written to n separately and at once. Furthermore, whether or not a value needs to be changed by writing among the n bit groups to be controlled, or whether a value does not need to be changed by writing, is determined and processed by the software of the CPU 2.

[0004] If there is a mixture of written changes and unchanged bits in the above n control bit groups, once writing is done to control register 1, the control bits holding data that do not need to be changed Since the data of the group will also be rewritten, the software of the CPU 2 reads the control data of the control register 1 and temporarily stores it in the memory 3, and then the control data that is written and changed.
The unmodified written data read from the memory 3 is added and these data are written to the control bit groups 11 to 1n of the control register 1 separately and at once. At this time, the unchanged control data is rewritten to the stored original control bit group.

[0005]

[Problem to be Solved by the Invention] Therefore, when a group of n controlled bits contains a mixture of written changes and unchanged bits,
Conventionally, there are problems in that the software load and write processing time increase. Further, a control register in which only one piece of control data is written has the same problem as above.

[0006] The present invention has been made in view of the above points.
It is an object of the present invention to provide a control register writing device that solves the above-mentioned problems by providing control data that prohibits writing to a group of bits controlled by writing unchanged data.

[0007]

[Means for Solving the Problems] FIG. 1 shows a diagram of the basic configuration of the present invention. In the figure, 11 is a write control section, and 12 is a control register section. The control register unit 12 has a control bit group n that allows data to be written at once by a write signal.
control data 1 to n (where n is a natural number of 1 or 2 or more).

When writing the n pieces of control data 1 to n, the write control unit 11 uses a write signal as a write permission signal to write to the bit group to be controlled if the control data is a value that is subject to write permission. When the value of the control data is not subject to write permission, a write signal is input to the corresponding control bit group as a write prohibition signal.

[0009]

[Operation] In the present invention, as shown in FIG. 1, when the write data, that is, the value of the control data, is a value that is subject to write permission, the write control unit 11 sends the control register unit 1
Control data is written into the control bit group to be written using the write signal to 2 as a write permission signal.

On the other hand, when the value of the control data is not subject to write permission, the write control section 11 sets the write signal to the control register section 12 as a write prohibition signal, and the control data is set as a control bit group to be written. is not written to.

Therefore, in the present invention, the control register that can be written at once is made up of a plurality of bit groups to control, and each controlled bit group has write-changed (values subject to write permission) and write-unchanged (write-unchanged) values. If there is a mixture of control data that performs the following operations (values that are not subject to permission), by setting the control data to be written to the control bit group that has not been changed to a value that is not subject to write permission, the control register can be written in a single write. can be changed and left unchanged at the same time.

0012

Embodiment FIG. 2 shows a configuration diagram of an embodiment of the present invention. In the figure, the same components as in FIG. 1 are designated by the same reference numerals. In FIG. 2, the write data are data numbers D7 to D.
It consists of 8 bits of 0, and a total of 4 control data of 2 bits each. Registers A to D each having a width of 2 bits are provided in the control register section 12 corresponding to each control data. The control register section 12 is a control register section specified by an 8-bit address, and the relationship between the above-mentioned registers A to D each having a width of 2 bits and data numbers is shown in the following table.

[0013]

[Table 1] As can be seen from the table above, register A has data number D0
The 2-bit first control data of data numbers D2 and D3 are input to register B, and the 2-bit second control data of data numbers D4 and D5 are input to register C. The third control data is input, and further, the register D receives 2-bit fourth control data of data numbers D6 and D7.

The control register unit 12 performs preset control as shown in FIG. 3 based on the values of control data stored in registers A to D. As can be seen from FIG. 3, when the control data value is “00”, register A
-D, the control operation remains unchanged, that is, the same control operation as last time is performed. Further, when the control data has a value other than "00", the controlled device is caused to perform preset control such as inputting received data and outputting transmitted data.

On the other hand, the write control section 11 is composed of four write control circuits 111 to 114, as shown in FIG. Write control circuits 111 to 114
are provided in a one-to-one correspondence with the registers A to D, respectively, and input write signals W1 to W4 to the registers A to D to enable or inhibit the write operation of the registers A to D.

That is, write control circuits 111 to 1
14 each receives 2-bit first to fourth control data, and when the value is "00", it outputs a write prohibition signal, and when the value is other than "00", it outputs a write permission signal. . As a result, the input control data is written into the registers A to D only when the write permission signal is input.

Next, the operation of this embodiment will be explained with reference to FIG. 4. Now, the register A of the control register section 12 has "10" (control 11 in FIG. 3), the register B has "01" (control 7 in FIG. 3), and the register C has "10" (
It is assumed that "11" (control 3 in FIG. 3) is set in control 5) in FIG. 3 and register D, respectively. The storage state of this control register section 12 is as follows: data number D7 is MSB, D
If 0 is expressed as an 8-bit value as the LSB, it is (E6)H in hexadecimal as shown by 21 in FIG.

In this storage state, register A is set to "11" without changing the set values of register B and register C.
If you write "10" to change to the state of control 12 in Figure 3 and write "10" to register D to change to the state of control 2 in Figure 3, the set values of registers B and C will not be changed. Register B and register C each have “0”.
0” is written. Therefore, in this case, data number D7
is expressed as an 8-bit value with MSB and D0 as LSB, then in hexadecimal number (8
3) Write data with a value of H is input to the write control unit 11 from, for example, a CPU (not shown).

As a result, the write control circuits 111 and 114 in the write control unit 11 activate the write signals W1 and W4 (in other words, output write permission signals to the registers A and D, respectively).
Each value is written to . At the same time, the write control circuits 112 and 113 make the write signals W2 and W3 inactive (in other words, output write inhibit signals to registers B and C, respectively),
No values are written to registers B and C.

Therefore, registers A and D each contain "11".
and “10” are written, and data writing is prohibited in registers B and C, and the previous values “01” and “10” are held. As a result, the storage state of the control register unit 12 is set to data number D7 with MSB. , D0 is expressed as an 8-bit value with LSB as a hexadecimal value (A7
)H.

As described above, according to this embodiment, even if the four pieces of control data are changed and left unchanged, the four pieces of control data can be changed and left unchanged at the same time in one writing process. The software load on the CPU can be reduced, and the write processing time can also be shortened.

It should be noted that the present invention is not limited to the above-mentioned embodiments; for example, there may be a plurality of control register sections 12, or the number of registers may be only one; The number of bits of the control data stored and held therein may be different from each other, or may be partially different. Furthermore, there may be a plurality of values that are write-prohibited.

[0023]

[Effects of the Invention] As described above, according to the present invention, control data can be changed or left unchanged in a single write process, which reduces the software load and shortens the write process time compared to the conventional method. This feature has the advantage that it greatly contributes to improving the performance of the controlled device because it allows efficient writing to the control register section.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle configuration of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is an explanatory diagram of the operation of a control register section.

FIG. 4 is an explanatory diagram of the operation in FIG. 2;

FIG. 5 is a configuration diagram of an example of a conventional device.

[Explanation of symbols]

11 Write control section 12 Control register section A to D register

Claims (2)

[Claims] 1. A control register section (12) comprising one or more control bit groups written in a control register in response to a write permission signal for each control data in a control register into which a control data string can be written at once. , 1 or 2 above
When writing the above control data, the control data is
If the value is subject to write permission, the write signal to the corresponding control bit group is used as the write permission signal,
When the value of the control data is not subject to write permission, the write control unit (11) makes a write signal to the corresponding control bit group a write prohibition signal, and A control register writing device characterized in that only data for which writing is permitted is written into a corresponding control bit group in the control register section (12). 2. The control register writing device according to claim 1, wherein the control data is a plurality of pieces of data each having an arbitrary number of bits.