JPS5854440A - Display picture changing device in display device - Google Patents

Abstract

PURPOSE:To freely change a display picture partially in the order of the generation of change without increasing the contents of a program, by storing information of displayed data to be changed in a FIFO buffer. CONSTITUTION:A data controlling device 1 and a display device 2 are controlled by CPUs 10, 20, respectively. Data and interruption signals indicating the change of data are inputted from an external sensor to the CPU10. The CPU20 is provided with a program storing ROM21 for display control and a display data storing RAM22. Between both CPUs 1, 2, data are transmitted by using standarized frame format telegrams. In addition, transmission controlling interfaces 13, 23 are connected in order to control the transmission.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display screen changing device in one display device.

When displaying a large amount of externally input data, such as detection data from a large number of sensors, on a display device equipped with a CRT (cathode ray tube) or the like.

It would be inefficient to redisplay the entire screen each time there is a change in the content of a portion of a large amount of data. Therefore, it becomes necessary to change the display of only the changed portion (hereinafter referred to as partial update).

There are several methods for capturing changes in externally input data and partially updating the displayed content based on that data. One of them is to check whether there is a change in a large amount of data in the μth order, and if there is a change, perform a partial update of the display, and then sequentially control the check for data changes and the partial update of the display. It is something to do. With this method, partial updating of display data can be performed easily and immediately following changes in data.

However, due to the control of the display device, the control of sensors that are external data generation sources, and the overall system, it is necessary to separate the task of capturing changes in data from the outside and the task of partially updating the display. This may occur. In such a system, an interrupt is generated when external data changes, and the process proceeds to the IFI input processing routine. In this interrupt processing, the data after the change is taken in and stored in the memory ζea.
Set a flag indicating that IL and data have changed. In the one-display partial update task, each of the seven lags is checked, and if a flag is set, the display of data corresponding to that flag is updated. In this method,
If a flag is provided corresponding to each piece of data, it is possible to partially update all data.

As the amount of data increases, the number of flags must also increase, and all seven lags must be checked in the partial update task, resulting in an increase in program size. Furthermore, the 1 partial update task will periodically check for 7 lags.

Partial updates of the data display are not necessarily performed in the order in which changes occur.

Although it is possible to partially update the display screen by interrupt processing, it takes a long time to update one part, as in a system that transmits data to and from one display device. In this case, there is a problem that the time period during which interruption by other data is prohibited becomes long, and it becomes impossible to make the partial update of the display follow changes in the data.

This invention enables processing to be performed in a short time without increasing the size of the program in a system that has separate tasks for capturing changes in data and for partially updating the display. It is an object of the present invention to provide a display screen changing device in a display device 6ζ that can perform updates.

Embodiments of the present invention will be described in detail below with reference to one drawing.

In FIG. 1 ξ, in this embodiment, the data control device (
1) and the display device (2) are connected by a transmission line (3)I. The re-device tl+ (21 is controlled by the CPUQ and 0, respectively. The CPU (1-) is equipped with a ROM (Ill) storing programs for interrupt processing and partial update tasks, which will be described later, and a RAMff21 storing data to be displayed. This CPU QII manually generates various types of data and interrupt signals indicating changes in the data from external sensors, etc.
The handle is for controlling the display and has a ROM+211.1 which stores the display control program. and a RAM (22) that stores data necessary for display. In this embodiment, a CRT@ is shown as a display, and this CRT@
is controlled by its control circuit based on instructions from the CPU. As a transmission control method between the re-equipment Ill f2+, for example, HDLC (High Level D
data is transmitted in a standardized frame format. Device (1) is the primary station, and device t (2+ is 2
The next station, the primary station, performs line control by calling the secondary station by polling. For this transmission control.

Each of the devices 11+ +21 is provided with a transmission control interface Q3@.

FIG. 2 shows part of the contents of RAMQB. nh
Within the MQB, there is a storage area for input data. This area stores n pieces of data (DAl) to (DAn). These data themselves, that is, the contents of the data, are represented by (D A 1 ) and ~(DAn), respectively. Sea ≠ rumor concubine → rumor ko (for Llζ, ・These data (DAl) ~ (DAa) identification codes are (dal
) to (d a n). These identification codes include each data (DAI) to (DAI) in the data storage area.
II) is the address where it is stored.

The number of the sensor that generates the data is used.

For the CPU of the data control device (1), as shown in Figure 3, a first-in first-out buffer (first-in first-out buffer) is used.
rsL ouL buffsr, below FIFO buff 7
) αΦ, and its read pointer (R
P) and a write pointer (wp). F
The IFO buffer (141) stores identification codes of changed data, that is, data in which an interrupt has occurred as described later, and includes several storage locations for storing these identification codes.FIFO buffer a41
The storage capacity is sufficient to store the maximum number of data identification codes for which one interrupt can occur simultaneously. The identification code of the data is written to FIFOQ4) in the order in which the interrupt occurs, and is read out in the order in which it is written, so it is possible to partially update the display of the data in the order in which the interrupt i occurs. becomes.

Write pointer (wp) is FIFO buffer Q4
) specifies the storage location to be written, and the read pointer (RP) specifies the storage location to be read. In FIG. 3, in the initial state, both pointers (WP) and (RP) point to the storage location at the beginning of the FIFO buffer 041. As will be described later, when there is an interrupt that data has changed, that data (for example, the identification code Cdm1 of (DAI)) is written to the location specified by the write pointer (wp), and the data is written to the location specified by the write pointer (wp). +1 for the content. The write pointer (wp) always specifies where to write next. The read pointer (RF) still points to where (d-a l ) is stored.

When reading a partial update task, the identification code (dal) of the location specified by the read pointer (RP) is read, and the read pointer (RP)
) is added +1 to the content.

The read preference pointer (RP) always indicates where the primary should read. In this way, both pointers (WP
)(RP) is incremented by 1 each time it is written or read, and after designating the last storage location, it is cleared to designate the first storage location, thus rotating the designated locations. As is clear from the above operation, %FfFO buffer (+41
If the identification code is stored in any location, the contents of the pointer (wp) and (RP) are not equal.

When the contents of pointers (wp) and (RP) are equal ((W
P) = (RP) ), the PIFO buffer α fathom is empty.

FIG. 4 shows an example of display on the CRT @ in the display device (second column).Data (DAI) to (DAD) are
They are each displayed at a predetermined position on the display screen of the CRT (i151).If there is a change in these data, the display contents will be changed only for the data that has changed, and the display contents after the change will be changed. Data is displayed.

FIG. 5 shows an example of the format of a message transmitted from the data control device (1) to the display device (2). This message consists of six fields: start flag 7 yield (S), address field, control field (CO), information field (INF), check field (CH), and end flag field tEl. It consists of

This message has data A from the 2nd row and 15th column. The messages exchanged between both devices +11 and +21 are always configured in the same format.

FIG. 6 shows the interrupt processing procedure executed by %CPUQI. As mentioned above.

An interrupt occurs when the input data changes. The priorities of all data (DAI) to (DAn) are at the same level, and when an interrupt caused by a certain data I occurs, interrupts caused by other data G are prohibited.

Therefore, between the interrupt routines for each data
No contention for writing to IFO buffer a (a) occurs. Since the interrupt routines for each data attack are exactly the same, only the data (DAI) will be explained.

Data (DAI) When an interrupt occurs, the changed data (DAI) is read and written to the storage location of data (DAI) in the data storage area of RAMa2, and the contents of data (DAI) are updated. (Step C11l
). Next, the identification code (a a 1) of the data (DAl)
is FIFO/(77a(II write pointer(wp
) # will be written to the specified storage location and the
+1 is added to the pointer (wp) (step). This completes the interrupt processing.

FIG. 7 shows the processing procedure of a display partial update task executed by CPU0I. This partial update task is performed during polling of the display device (2). Depending on whether the contents of the pointer (wp) and the pointer (RP) are equal, the F summer FO buffer a-
It is checked whether the identification code of the data that has changed is stored (step (goods)), and if it is stored, interrupts by each data are prohibited (step (goods)).
(translation)). When the identification code of the data at the location specified by the read pointer (RP) is read and the contents of the read pointer (BP) are incremented by 1 (step f4
31), the prohibition of interrupts is canceled. Finally, the data in the memory field is searched from the read identification code, and
The data after the corresponding change is read. Then, using this data, the message to the display device (2+) is edited and transmitted to the device (2) (step sir).Display device +21
Then, when this message is received, the display of the corresponding data on the CRT@ screen is changed according to the contents of the message. Immediately before reading the identification special code from the FIFO buffer (141), interrupts due to data changes are prohibited, so this reading, writing by interrupts, and the FIFO by Cζ
Simultaneous accesses to Ox7a041 can be avoided. Then, when the reading of the identification code is completed, the prohibition of interrupts is canceled, so that interrupts due to changes in data are enabled, and writing to the FIFO buffer a- is performed normally.

In the above embodiment, the FIFO buffer stores the identification code of data that has changed, but in a system where the amount of data information is extremely small, the contents of the data are stored in the FIFO buffer.
It is also possible to put it in the FO buffer.

As described above, in the present invention, a FIFO buffer is provided, and information regarding data whose display should be changed is stored in this FIFO buffer. Since it is very easy to search whether any information is stored in the FIFO buffer, it is necessary to increase the number of partial update task programs for one display. Furthermore, in the %FIFO buffer, the stored information is read out in the order in which it was written, so it is possible to partially update the display of data in the order in which changes occur.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a data control device and a display device, FIG. 2 is a diagram showing the contents of the RAM of the data control device,
Figure 3 is a diagram showing the operation of the FIFO buffer, Figure 4 1i
FIG. 5 is a diagram showing a message format, FIG. 8 is a flow chart showing an interrupt control task, and FIG. 7 is a flow chart showing a partial update task. (1)...Data control device, (21...Display device,
Shout 121111 @ @ CPU , Ql1211 +
1@11 ROM -*'1jQ2J 1111@RA
M. α gradient...FIFO buffer, @...CRT. Patent applicant: Tateishi Electric Co., Ltd.

Claims (1)

[Claims] On the display screen - A first-in, first-out buffer that stores information about data that has changed among the plurality of data on a device number that displays the plurality of data, based on an interrupt caused by the data that has changed. and means for storing information regarding the data in the buffer; and means for searching the buffer, determining a specific length of data from the information stored therein, and changing the weight of the data. 1 Display device ■Display screen changing device.