JPH08161480A - Graphic rotation dma controller - Google Patents

Abstract

PURPOSE: To execute rotation processing of graphic data during DMA transfer at a high speed by adopting the configuration that an address generated at DMA transfer and graphic data written to a display storage means are controlled to control the rotation of a graphic stored in the storage means by a specific angle. CONSTITUTION: The controller is provided with a DMA transfer controller 13 whose internal register stores a command and various parameters to control DMA transfer between a memory 11 and a display memory 12, a microprocessor 14, a display device 15 displaying a graphic on its screen, and a display controller 16 providing an output of graphic data stored in the display memory 12 as a video signal to the display device 15. Then the DMA transfer controller 13 controls an address generated at DMA transfer to the memory 11 and data to be written in the display memory 12 to rotate the graphic stored in the memory 11 by ±90 deg.. Thus, the processing speed of displaying a rotated graphic stored in the memory 11 is increased by the control of the microprocessor 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an on-vehicle navigation device for displaying a map, a current position mark of a vehicle, a character, etc., and a graphic rotation DMA for controlling the rotation of a graphic.
Regarding the control device.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing the configuration of a conventional graphic rotation DMA controller. 5, in this example, a memory 1 for storing drawing data of a figure, a display memory 2 for storing the drawing data stored in the memory 1 by DMA transfer, and a DMA transfer control device 3 for controlling the DMA transfer. A microprocessor 4, a display device 5 for displaying a graphic on a screen, and a display control device 6 for outputting a video signal are provided. The memory 1 has a drawing area 1a and a drawing area 1b, and the display memory 2 is provided with the drawing area 2a. Further, the memory 1, the DMA transfer control device 3 and the microprocessor 4 are connected by a data bus and an address bus. The display memory 2 and the DMA transfer control device 3 are connected by a display memory data bus and a display memory address bus. The display memory 2 and the display control device 6 are connected by a display memory address bus, and display data is output from the display memory 2 to the display control device 6.

Regarding the conventional example constructed as described above,
The operation will be described below. When the video signal obtained by rotating the graphic is output from the display control device 6 to the display device 5, the graphic data stored in the drawing area 1 a of the memory 1 is stored in the drawing area 1 b of the memory 1 by the microprocessor 4.
Sequentially controls to store the rotated drawing data.
Further, the microprocessor 4 uses the DMA transfer control device 3
Write the command to the internal register of. This writing activates the DMA transfer control device 3 to execute DAM transfer of drawing data from the drawing area 1b of the memory 1 to the display memory 2.

As described above, also in the conventional graphic rotation DMA control device, the microprocessor 4 rotates the graphic from the drawing area 1a of the memory 1 to the drawing area 1b and stores the drawing data, and the drawing area of the memory 1 is stored. DAM transfer of drawing data is performed from 1b to the display memory 2.

[0005]

However, in the conventional graphic rotation DMA controller, the microprocessor 4 rotates the graphic from the drawing area 1a of the memory 1 to the drawing area 1b and stores the drawing data. Therefore, there is a drawback that the arithmetic processing of the microprocessor 4 becomes complicated, and that the time until the video signal is output to the display device 5 is delayed by the processing for rotating the graphic, storing the drawing data, and reading the drawing data. is there.

The present invention solves such a conventional problem. When the graphic stored in the memory is rotated by 90 degrees and displayed by the control of the microprocessor, D is displayed.
It is an object of the present invention to provide an excellent graphic rotation DMA control device capable of performing high-speed rotation processing of drawing data during MA transfer.

[0007]

In order to achieve the above object, a graphic rotation DMA controller according to claim 1 stores a drawing means for storing drawing data and a drawing data read from the DMA transferred storage means. Display storage means for storing as drawing data for display; and DMA transfer control means for writing commands and various parameters in an internal register to control DMA transfer between the storage means and the display storage means,
A microprocessor for performing arithmetic processing of drawing data and a display control means for outputting the drawing data stored in the display storage means as a display signal are provided, and the DMA transfer control means has an address generated at the time of DMA transfer to the storage means. The drawing data to be written in the display storage means is controlled to rotate the figure stored in the storage means by plus 90 degrees or minus 90 degrees.

According to another aspect of the present invention, there is provided a graphic rotation DMA control device in which the microprocessor calculates the drawing position and calculates the drawing position based on the detection data from the positioning device in the navigation device. .

[0009]

With this structure, the figure rotation DMA control device according to claims 1 and 2 controls the address generated by the DMA transfer control means to the storage means during the DMA transfer and the drawing data to be written in the display storage means. Then, the figure stored in the storage means is rotated by plus 90 degrees or minus 90 degrees. Therefore, when displaying a figure stored in the memory by rotating it by 90 degrees under the control of the microprocessor, a process of rotating the figure by 90 degrees between the drawing areas in the memory is performed conventionally as is conventionally done. There is no need to do it. That is, the rotation process of the drawing data during the DMA transfer is executed at high speed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a graphic rotation DMA controller according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a graphic rotation DMA controller according to the present invention. In FIG. 1, in this example, a memory 11 for two-dimensionally storing drawing data and a display memory 12 for two-dimensionally storing the drawing data stored in the memory 11 by DMA transfer as drawing data for display. Is provided. Memory 1
1 has a drawing area 11a, and the display memory 12 is provided with a drawing area 12a. Further, in this figure rotation DMA control device, a DMA transfer control device 13 for writing commands and various parameters to an internal register to control DMA transfer between the memory 11 and the display memory 12, a microprocessor 14, A display device 15 for displaying a graphic on the screen and a display control device 16 for outputting the drawing data stored in the display memory 12 to the display device 15 as a video signal are provided. Also, the memory 11 and the DMA
A data bus 17 and an address bus 18 are connected between the transfer control device 13 and the microprocessor 14, and a display memory data bus 20 and a display memory address bus 21 are connected between the display memory 12 and the DMA transfer control device 13. Connected by. The display memory 12 and the display control device 16 are connected by a display memory address bus 21, and display data is output from the display memory 12 to the display control device 16.

Regarding the embodiment configured as described above,
The operation will be described below. Here, the DMA transfer control device 13 controls the address generated at the time of the DMA transfer to the memory 11 and the data to be written in the display memory 12 to rotate the figure stored in the memory 11 by ± 90 degrees. First, at the time of DMA transfer, the drawing data in the drawing area 11a of the memory 11 is in 1-word units on the data bus 17
Through the DMA transfer control device 13. In the DMA transfer control device 13, the arrangement order of the dot data for N dots existing in one word is changed, and the display memory 12 is changed.
To the drawing area 12a.

Hereinafter, the DMA transfer control device 13 at the time of transfer
However, the relationship between the read address generated in the memory 11 and the write address generated in the display memory 12 and the state of rearrangement of dot data in the DMA transfer control device 13 will be described.

FIG. 2 is a block diagram showing the transfer order of the transfer source and its data. FIG. 3 shows the transfer order of the transfer destination at +90 degrees and its data, and FIG. 4 shows the transfer order of the transfer destination at -90 degrees and its data. Clockwise 90
In the DMA transfer at the time of rotation, the drawing data in which one word is composed of N dot data is transferred in the order shown in FIG. 2 (1) (2)
(3) The N words of dot data are read from the drawing area 11a of the memory 11 by N words in the address order of (3) and (4), and the dot data of N words are transferred in the DMA transfer control device 13 as shown in FIG. The data is written in the drawing area 12a of the display memory 12 in the order of 3 "and 4". The cycle of alternately executing the reading and writing is every N words. Note that the explanation here is "N
= 4 ”. Further, in the address calculation method, the transfer order (1) is set to
Assuming the transfer start address, transfer order (2) = (1) + drawing area width A, transfer order (3) = (2) + drawing area width A, transfer order (4) = (3) + drawing area width A Becomes

Thereafter, the transfer sequence (12) is repeated until the transfer sequence (13) = (1) +1, and the transfer sequence (1)
The calculation of 4) = (13) + drawing area width A is repeated below. The display memory 12 which is the transfer destination has the transfer order “2” =
“1” + drawing area width C, transfer order “3” = “2” + drawing area width C, transfer order “4” = “3” + drawing area width C, every N words (“N = 4”) And the transfer order is "5" =
The calculation of "1" -1 is executed. Note that the calculation of the transfer destination for each N words is based on the calculation when the transfer source column is changed.
That is, here, the transfer order is “12” to the transfer order “13”.
The calculation in the case of is expressed by the following equation (1).

Transfer order “13” = “12” + 2 × drawing area width C−1 (1) In this manner, the clockwise 90 ° rotation DMA transfer is executed. Note that the operation of the transfer source is the same as that of FIG. 2 in the DMA transfer when rotating counterclockwise 90 degrees, but the address order and data order of the transfer destination are [1], [2], and [3] as shown in FIG. [4]
Will be changed in the order of. The address calculation method is also transfer order [2] = [1] -1, transfer order [3] = [2] -1, and calculation for each N dot is transfer order [5] = [1] +1. Become. The calculation when the transfer source column is changed is expressed by the following equation (2).

Transfer order [13] = [12] + 2 × drawing area width C + 1 (2) In this way, the DMA transfer control device 13 causes the display memory 1 to display the graphics written in the drawing area 11a of the memory 11.
The second drawing area 12a is rotated by 90 degrees and DMA transfer is performed. The DMA transfer time from the memory 11 to the display memory 12 at this time is the same as the normal DMA transfer time when the burst mode or the like is not used. As described above, in this embodiment, when the graphic written in the memory 11 is rotated by 90 degrees and is displayed, the graphic is rotated between the drawing areas in the memory 11 as is conventionally done. hand,
There is no need to draw (see FIG. 5). Therefore, the processing time for the microprocessor 14 to rotate the graphic is not required, and the graphic can be rotated at high speed.

As a result, when the device is applied to a vehicle-mounted navigation device using a GPS receiver, an azimuth sensor, a speed (distance) sensor, etc., and heading up of a figure is performed every 90 degrees, roads and topography of the map Memory 1
Since the rotation depiction within 1 is not performed, this memory 11 can be made unnecessary. As a result, the amount of calculation of the microprocessor 14 is reduced and other processing can be added.

[0019]

As is apparent from the above description, according to the figure rotation DMA control device of the first and second aspects, the DMA
Since the transfer control means controls the address generated at the time of the DMA transfer and the drawing data to be written in the display storage means with respect to the storage means to rotate the figure stored in the storage means by plus or minus 90 degrees, When the figure stored in the memory is rotated by 90 degrees and displayed by the control of the microprocessor, there is an effect that the rotation process of the drawing data during the DMA transfer can be executed at high speed.

[Brief description of drawings]

FIG. 1 is a block diagram of a graphic rotation DMA controller according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a transfer order of a transfer source and a data structure thereof in the embodiment.

FIG. 3 is a block diagram showing a transfer order of a transfer destination and a data structure thereof at +90 degrees in the embodiment.

FIG. 4 is a configuration diagram showing a transfer order of a transfer destination and its data structure at −90 degrees in the embodiment.

FIG. 5 is a block diagram of a conventional graphic rotation DMA controller.

[Explanation of symbols]

 11 Memory 12 Display Memory 11a Drawing Area 12a Drawing Area 13 DMA Transfer Control Device 14 Microprocessor 15 Display Device 16 Display Control Device 17 Data Bus 18 Address Bus 20 Display Memory Data Bus 21 Display Memory Address Bus

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G08G 1/0969 G09B 29/00 A 29/10 A G09G 5/36 520 K 9377-5H

Claims (2)

[Claims] 1. A storage means for storing drawing data, and a DM.
A display storage means for storing the transferred drawing data read from the storage means as drawing data for display, and a DMA between the storage means and the display storage means by writing commands and various parameters in an internal register The DMA transfer control means includes a DMA transfer control means for controlling the transfer, a microprocessor for calculating the drawing data, and a display control means for outputting the drawing data stored in the display storage means as a display signal. Controlling an address generated at the time of DMA transfer and drawing data to be written in the display storage unit to the storage unit to rotate a figure stored in the storage unit by plus or minus 90 degrees. Characteristic graphic rotation DMA controller. 2. The figure rotation according to claim 1, wherein the microprocessor calculates and calculates the self-position based on the detection data from the self-position detecting means in the navigation device, as well as the calculation processing of the drawing data. DMA controller.