JPS6314997B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sewing pattern forming device for a sewing machine, and particularly to an improvement in a monitor display section during pattern formation.

In industrial automatic sewing machines, etc., sewing is performed repeatedly along a desired sewing pattern many times, and the sewing pattern is stored in a pattern memory such as P-ROM in order to arbitrarily change this sewing pattern to a desired shape. When sewing, the sewing pattern in this memory is read out and the desired shape is efficiently sewn multiple times, and when the sewing pattern is changed, the contents of this P-ROM are changed according to the desired shape. There is. Such a sewing pattern generator is operated by drawing a desired sewing pattern on an input board and electronically writing it into a memory.

When inputting the sewing pattern, the input data is displayed on a monitor in order to form an accurate pattern, and for this purpose the display CRT displays stitches along the input pattern.

However, conventional display units of this type have the disadvantage that the resolution of the display image is low and cannot accurately indicate stitches, and the input data
- Since a common CPU was used to control storage in ROM etc. and monitor display on a CRT, it took time to transfer the display data, resulting in coarse image density and flickering. The drawback was that the quality deteriorated significantly.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a monitor display section that forms an extremely stable monitor image without flickering, has high resolution, and can accurately display even fine seams. An object of the present invention is to provide an improved sewing pattern forming device for a sewing machine.

In order to achieve the above-mentioned object, the present invention inputs desired sewing pattern information written from an input board.
In a sewing pattern forming device for a sewing machine, which writes sewing pattern data to the pattern memory under CPU control to form sewing pattern data for an automatic sewing machine and also displays stitch data sequentially on a monitor display while inputting the data, the data is written to the pattern memory. It has two separate data memories for storing relative value data for reading data and a display memory for storing absolute value data for monitor display. Data transfer from the CRT to the CRT is performed by a DMA controller installed independently of the CPU.
The DMA controller functions as a slave to the CPU when writing absolute value data from the input board to the display memory, and functions as a master independent of the CPU when transferring data in the display memory to the CRT. The feature is that the DMA controller repeatedly restarts the transfer without requiring an interrupt to the CPU.

Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a pattern former according to the present invention, and FIG. 2 shows its internal circuit.
A tablet digitizer 10 forming an input board is provided at the front of the device, and a stylus pen 12 is provided.
By drawing the desired sewing pattern on the tablet, this is converted into an XY image signal.
Under the control of the CPU 14, the P-ROM writing circuit 16
P- to form a predetermined pattern memory through
It is written to the ROM as a sewing pattern signal. The P-ROM is installed in a P-ROM socket 18 provided on the rear surface of the digitizer 10. Various modes and other information at the time of this input are displayed on the LED display board 20. The CPU 14 converts the input data from the digitizer 10 into P-
The program for writing to the ROM is written in the system program ROM 22, and the CPU 14 performs processing according to this program.Input data from the digitizer 10 is temporarily stored in the data memory 24 consisting of RAM, In the embodiment, the values are stored as relative value data indicating the XY coordinate data of the digitizer 10 by the amount of XY change of each stitch.

The input data of the digitizer 10 is stored in P-ROM.
A monitor display CRT26 is provided to monitor data when writing to the
Desired sewing patterns can be sequentially input from the digitizer 10 while viewing the monitor image on the CRT 26. In the present invention, a random scan type CRT is used as the CRT26,
Compared to normal raster scan type CRTs, it displays images with higher resolution and accurately displays even fine seams, and can simplify peripheral circuits such as video RAM, reducing the price of monitor equipment. can. A CRT controller 28 is provided to drive the CRT 26.
8 is supplied with control signals corresponding to the X and Y coordinates of the monitor image from an X data D/A converter 30 and a Y data D/A converter 32, respectively, and a brightness control signal from a brightness control circuit 34. There is.

In the present invention, the monitor display of the sewing pattern by the monitor display CRT 26 is operated by display data from a display memory 36 provided separately from the data memory 24 for the P-ROM, and this display memory 36 is transmitted from the digitizer 10. RAM that stores input data as absolute value data of XY coordinates
Consists of. The output of this display memory 36 is connected to two latches 38 and 4 for each X data and Y data.
Converter 30, 32 via 0 and 42, 44
The brightness information is also supplied to the brightness control circuit 34, thereby controlling the CRT controller 28.
can make the CRT 26 draw a monitor image that is faithful to the input data.

In the present invention, the random scan
In order to display images on CRT26 at high speed,
It is characterized in that data transfer from the display memory 36 to the CRT 26 is performed by a direct memory access method using a DMA controller separately from the CPU 14 that controls writing to the P-ROM, thereby improving image quality and preventing flickering and other problems. It is possible to do so. In the embodiment, display memory 36 is controlled by CPU 14 when writing input data from digitizer 10 and when transferring this written data to CRT 26.
The display memory 36 is controlled by the DMA controller 46, and for this purpose, the display memory 36 is commonly connected to the CPU 14 and the DMA controller 46. However, in order to make the control by both controllers independent, a separation gate 48 is connected to the common bus. It is provided.

In the present invention, since the random scan CRT is displayed online by combining the CPU bus and the DMA bus, the CPU and DMA can operate independently at all times, and only when writing absolute value data to the display memory. The DMA only acts as a slave to the CPU; during other transfers, the DMA operates as a slave to the CPU.
The transfer operation can be performed automatically and repeatedly each time without receiving any control from the controller.

The sewing pattern forming device according to the present invention has the above-mentioned configuration, and the operation of writing input data from the digitizer 10 into the P-ROM will be briefly explained below.

When the operator draws a desired sewing pattern on the surface of the digitizer 10 with the stylus pen 12, the digitizer 10 captures this sewing pattern as an electrical signal on the XY coordinates, which is sent to the CPU 14.
is written into the data memory 24 as relative value data for each stitch. The CPU 14 reads the relative value data written in the data memory 24 based on the program in the program ROM 22.
The sewing pattern is supplied to the ROM writing circuit 16, whereby a desired sewing pattern can be written into the P-ROM.

At the same time as writing the P-ROM, in the present invention, input data from the digitizer 10 is sequentially written.
Image can be monitored by CRT26,
This image monitor uses the data memory 2 for monitoring.
4, a display memory 36 and a random scan type CRT 26 are used, and a DMA
By transferring data from the display memory 36 by the controller 46 independently from the CPU 14 for P-ROM writing, it becomes possible to form a display image at high speed and display extremely accurate seams. .

An example of DMA in the present invention will be explained below with reference to FIG.

FIG. 3 shows an example of data processing in the present invention, which basically consists of a DMA controller 4
6 is a hardware device that constantly requests requests and thereby stops the transfer using a mask bit in the DMA. The transfer is started by clearing the mask bit, but in this embodiment, the DMA is programmed so that the mask bit does not go up when the transfer for one pattern is completed. This allows the DMA to repeat transfers independently without requiring a CPU interrupt for each pattern transfer.

As is clear from FIG. 3, when data for one coordinate is input from the digitizer 10, the CPU 14
calculates this and writes relative value data to the data memory 24 in order to write data to the P-ROM.
Next, in order to make the DMA controller 46 a slave, the CPU resets the DMA, sets a mask bit, and stops the master operation of the DMA controller 46. This allows the DMA controller 4
6 becomes a slave with CPU 14 as the master,
In this state, the CPU 14 writes the input data from the digitizer 10 to the display memory 36 as absolute value data. After this write is completed, the mask bit is cleared and the DMA controller 4
6 becomes a master operation and transfers the absolute value data written in the display memory 36 to the CRT 26 for one pattern. After the transfer of this one pattern is completed, the DMA controller 46 is programmed not to set the mask bit, so
The process is restarted without requiring an interrupt to the CPU 14, and the transfer of one pattern in the repeat memory 36 is sequentially and repeatedly performed again.

Therefore, the data transfer time is shortened, and even when the amount of data to be transferred is large, the necessary number of screens can be secured, and extremely high-quality monitor images without flickering can be obtained. Furthermore, since each transfer is performed by DMA, the CPU system program can be simplified and the circuit configuration can be simplified.

As described above, according to the present invention, it is possible to obtain an extremely high quality monitor image, and it is also possible to simplify the apparatus and obtain a low-cost sewing pattern forming device.

[Brief explanation of the drawing]

FIG. 1 is an external view of a sewing pattern forming device to which the present invention is applied, FIG. 2 is a circuit diagram of the main part of the present invention, and FIG.
The figure is a flow diagram of FIG. 2, and the same parts in each figure are given the same reference numerals, 10 is a tablet digitizer, 14 is a CPU, 24 is a data memory, 26 is a monitor display CRT, 36 is a display memory, 46 is
DMA controller 48 is an isolation gate.

Claims (1)

[Claims] 1 The desired sewing pattern information written from the input board is written to the pattern memory under CPU control to form sewing pattern data for the automatic sewing machine, and the stitch data is sequentially displayed on the monitor display while the data is being input. A sewing pattern generator for a sewing machine has separate data memory for storing relative value data for writing data into the pattern memory and a display memory for storing absolute value data for monitor display, and the monitor display The device consists of a random scan type CRT, and data transfer from the display memory to the CRT is performed by a DMA controller installed independently of the CPU, and the DMA controller transfers absolute value data from the input board to the display memory. When writing, it becomes a slave to the CPU and writes the data in the display memory.
A sewing pattern for a sewing machine that functions as a master function independent of the CPU when transferred to a CRT, and repeatedly transfers and restarts data in the display memory using a DMA controller without requiring an interrupt to the CPU. Formator.