JPH10207688A - Graphics processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high speed graphics processing. SOLUTION: A geometry processor 50 outputs a command code expressing processing to be required to a rendering processor 500, plural floating point data to be processed and scale factor data for specifying the decimal point bit position of fixed point data to be converted from each floating point data. A format converter 100 converts each floating point data into fixed point data having the decimal point bit position specified by the scale factor data and transfers the fixed point data to the processor 500.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphics processing apparatus for performing graphics processing such as 3D graphics, and more particularly to a technique for speeding up graphics processing.

[0002]

2. Description of the Related Art As a conventional graphics processing apparatus, for example, an apparatus described in JP-A-8-161525 is known.

These conventional graphics processing apparatuses generally include a geometry section for performing geometric calculations such as coordinate conversion and clipping processing, and a rendering section for converting graphics such as straight lines and triangles into pixels and performing drawing processing. Consists of

[0004] In such a graphics processing apparatus, when an image is generated by projecting the 3D graphics data from various 3D graphics data, first, the geometry section performs
Performs perspective transformation of the three-dimensional shape into two-dimensional coordinates, performs clipping processing, calculates luminance for the light source, and the like. Next, in the rendering unit, the geometry unit projects the three-dimensional shape into two-dimensional coordinates by using a straight line as graphic data. Data such as triangles and triangles are developed into pixels, and operations such as Z comparison and alpha blending are performed, and the image is stored in the frame memory.

In such a graphics processing device, the geometry section is usually realized as a single processor chip.
In order not to limit the range of numerical values or to lower the calculation accuracy,
Each data is handled as a floating point number.

[0006] On the other hand, the rendering unit is also usually realized as one processor chip, but its operation is performed by treating each data as a fixed-point number. This is because it is difficult to perform the operation performed by the rendering unit using floating point numbers in terms of the circuit scale and the operation speed.

[0007] The bit position of the fixed-point number handled in the rendering unit usually differs depending on the type of data. This is due to the fact that the accuracy required for generating a high-quality image differs for each type of data.

As described above, in the conventional graphics processing device, the number representation of the data handled by the two units is different, such that the geometry unit handles data using floating point numbers and the rendering unit handles data using fixed point numbers. Was. Therefore, conventionally, in the geometry unit, the data after the operation is converted from the floating-point number to a fixed-point number, and the data converted to the fixed-point number is passed to the rendering unit. For example, the above-mentioned JP-A-8-16
In the device described in Japanese Patent No. 1525, a number obtained by multiplying a floating-point number by 4096 is represented by an integer representation, so that data represented by the integer representation can be correctly represented as a fixed-point number having a decimal part of 12 bits. ing.

[0009]

As described above, in the conventional graphics processing apparatus, it was necessary to convert a floating point number into a fixed point number in the geometry section. In addition, the contents of the conversion to the fixed-point number differ for each type of data because the bit position of the decimal point of the fixed-point number required for rendering differs depending on the type of data.

Here, performing the conversion from the floating-point number to the fixed-point number in the geometry section as described above increases the load on the geometry section, and during this time, the arithmetic unit in the geometry section converts the floating-point number to the fixed-point number. Since it is used for conversion to a decimal point, the geometry section cannot perform original processing such as coordinate conversion, and lowers the throughput of the entire graphics processing apparatus. When the geometry section is operated by a program, a procedure for converting a floating-point number into a fixed-point number, which is different for each type of data, must be defined in the program.

Accordingly, an object of the present invention is to provide a graphics processing apparatus capable of reducing a reduction in processing speed required for converting a floating-point number to a fixed-point number.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a processor for outputting graphic data including a floating-point data string representing information for specifying a graphic to be drawn in a floating-point format. A rendering unit that expands the graphic into pixels in accordance with drawing data including a fixed-point data string representing the contents of a power figure in a fixed-point format, and outputs the graphic data. A data converter for converting floating-point data included in the fixed-point data to fixed-point data and outputting the drawing data to the rendering unit, wherein the data converter converts the floating-point data to bits of the decimal point of the fixed-point data. A graphics processing device characterized by having decimal point position changing means for changing the position. To.

According to the graphic processing device of the present invention, a data converter for converting floating-point data to fixed-point data is provided between the processor and the rendering unit. Processor processing and conversion from floating-point data to fixed-point data can be performed, enabling high-speed graphics processing. In addition, since the bit position of the decimal point of the fixed-point data to be converted can be changed for each floating-point data,
It can handle a wide variety of data.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a graphics processing apparatus according to the present invention will be described below.

First, a first embodiment will be described.

FIG. 1 shows a configuration of a graphics processing apparatus according to the present embodiment.

As shown in the figure, the graphics processing device according to the present embodiment comprises a geometry processor 50, a data converter 100, a rendering processor 500, and a frame memory 600.

The data converter 100 includes a control unit 400, a scale factor unit 300, a format conversion unit
Consists of 200.

FIG. 2 shows a configuration of a computer to which the graphics processing apparatus shown in FIG. 1 is applied.

As shown, in the computer, a CPU 10, a memory 20, an external storage device 12, and an input device 13 such as a keyboard, a mouse, and a pen input tablet are connected via a bus 14. Bus 1
4, a slot 15 for mounting an expansion card is provided, and the graphics processing apparatus 100 realized as an expansion card allows the bus 1 to be connected via the slot.
4 is connected. Further, a CRT 700 as a display device is connected to the graphics processing device.

In such a configuration, the CPU 10 executes the application read from the memory 14, and executes graphics commands such as triangles and straight lines, and graphics data including vertex coordinates, normal vectors, textures and the like given by floating point numbers. Is generated and given to the geometry processor 50 via the system bus.

The geometry processor 50 performs coordinate conversion, clipping processing, calculation of luminance with respect to the light source, and the like on the graphics data, and outputs commands such as triangles and straight lines, and coordinates and luminance data after geometry processing.
The data is converted into graphic data including a scale factor and a floating-point data string, and output to the data conversion unit 100.

The data converter 100 passes drawing data obtained by converting the graphic data passed from the geometry processor 50 into a fixed-point data sequence to the rendering processor 500.

The rendering processor 500 develops data such as straight lines and triangles indicated by the drawing data obtained by converting the graphic data into fixed-point numbers by the data conversion unit 100 into pixels,
Calculations such as Z comparison and alpha blending are performed with the frame memory 600, and processing for storing pixels obtained as calculation results in the frame memory 600 is performed.

The frame memory 600 is constantly read, and the contents of the frame memory 600 are displayed on the CRT 700 as a display device.

The graphics processing apparatus according to the present embodiment can be applied to a wide variety of apparatuses such as a game apparatus, a computer having a configuration other than that shown in FIG. 2, and a word processor, in addition to the apparatus shown in FIG.

The details of the graphics processing apparatus will be described below with reference to the data converter 10 which is the most characteristic part of the present invention.
The description will focus on 0.

First, the graphic data input from the geometry processor 50 to the data converter 100 and the data converter 1
Drawing data output from 00 to the rendering processor 500 will be described.

As shown in FIG. 3, a geometry processor
The graphic data given from 50 to the data converter 100 includes command code, scale data, floating point data 1 to 8
It is composed of

For example, the linear graphic data is used when converting a floating point data 1 to 7 into fixed point data 1 to 7 as scale data by inputting a line drawing command, a transfer number 7 and an address into a command code. The scale factor is entered, the floating point data 1 contains the X coordinate of the starting point of the floating point data, the floating point data 2 contains the Y coordinate of the starting point of the floating point data, and the floating point data 3 contains the X coordinate of the ending point of the floating point data. The floating point data 4 contains the X coordinate of the end point of the floating point data, the floating point data 5 contains the luminance R of the floating point data, the floating point data 6 contains the luminance G of the floating point data,
The floating point data 7 contains the luminance B of the floating point data.

As shown in FIG. 3, the data converter 100
Receiving such graphic data, command code,
The fixed-point data 1 to 8 obtained by converting the floating-point data 1 to 8 into fixed-point data are passed to the rendering processor 500 as drawing data.

For example, in the drawing data obtained by converting the graphic data of the straight line, the command code contains the drawing command of the straight line, the transfer number 7 and the address, the fixed point data 1 contains the X coordinate of the starting point of the fixed point data, and the fixed point data. Data 2 contains the Y coordinate of the start point of the fixed-point data, fixed-point data 3 contains the X coordinate of the end point of the fixed-point data,
The fixed-point data 4 contains the X coordinate of the end point of the fixed-point data, the fixed-point data 5 contains the luminance R of the fixed-point data, the fixed-point data 6 contains the luminance G of the fixed-point data, and the fixed-point data 7 The luminance B of the decimal point data is entered.

FIG. 4 shows the format of input / output data of the data converter 100 described above.

The command code is composed of an operation code, other control codes, the number of transfers, and an address. Operation code is rendering processor
Write the operation contents instructed to 500, the transfer number is the fixed-point number of data passed to the rendering processor 500,
The address indicates a register of the rendering processor 500 to which the graphic data is written. Other control codes include, as necessary, the geometry processor 50, the rendering processor 500, or the data converter 100.
To store the control information that you want to convey.

Next, the scale data is from Scale1 to Scale8.
Each Scale has a scale factor written on it. Scale1 corresponds to the floating-point data 1 and the fixed-point data 1 in FIG. 3, and Scale2 corresponds to the floating-point data 2 and the fixed-point data 2.
The same applies to Scale 8. Here, for example, if the value of Scale1 is 3, this indicates that the position of the decimal point of the fixed-point data 1 passed from the data converter 100 to the rendering processor 500 is the third bit from the least significant bit. Is 5, the fixed-point data 2 passed from the data converter 100 to the rendering processor 500
Is set to the fifth bit from the least significant bit.

Next, the floating-point data is converted to a known IEEE
E is a single-precision floating-point notation, consisting of 1 bit for the sign, 8 bits for the exponent, and 23 bits for the mantissa.

Finally, the fixed-point data includes a sign, an integer part, and a decimal part, and the bit position of the decimal point changes according to the scale factor.

Hereinafter, the operation of the data converter 100 will be described.

In the data converter 100, the control unit 400 decodes the command code of the graphic data including the command code, scale data, and floating point data generated by the geometry processor 50, and converts the floating point data into fixed point data. For this purpose, a set of scale factors and an instruction on which scale factor to use are given to the scale factor unit 300.

The scale factor section 300 operates in accordance with a set of scale factor strings from the control section 400 and a control signal for instructing which scale factor to use, and gives the format conversion section 200 a scale factor, that is, a decimal point of a fixed-point number. Gives the bit position of

The format conversion unit 200 converts the floating-point data from the geometry processor 50 into fixed-point data so as to correspond to the scale factor received from the scale factor unit 300, and supplies the fixed-point data to the rendering processor 500.

Hereinafter, details of each section will be described.

FIG. 5 shows the configuration of the control section 400.

The control unit 400 manages the state of the data converter 100, and controls the transfer of graphics and drawing data to the geometry processor 50 and the rendering processor 500, and the fixed-point number passed to the rendering processor 500. And a LEN register 430 that stores the number of transfers included in the command code.

The state managed by the sequencer 410 includes a state in which the data converter 100 receives a command code from the geometry processor 50, a state in which the data converter 100 receives scale data, and a state in which the data converter 100 receives floating point data 1 to 8. is there.

While receiving the command code, the sequencer 410 issues an instruction to set the number of transfers in the command code to the LEN register 430, and sends to the counter circuit 420
An initialization instruction of the CNT register indicating the number of fixed-point data passed to the rendering processor 500 is issued, a command code write request DC_W signal of the rendering data is issued to the rendering processor 500, and the command code is passed to the rendering processor 500. When a signal RP_ACC indicating that the drawing data command code has been received is returned from the rendering processor 500, a signal DC_ACC indicating that the command code has been received is output to the geometry processor 50, and the state is received as scale data. Transition to the state.

Next, while receiving the scale data, the sequencer 410 issues an instruction SET signal for writing the scale data to the scale factor unit 300, and sends a signal DC_ACC signal indicating that the scale data has been received to the geometry processor 50. And changes the state to a state receiving floating point data 1 to 8.

Next, while receiving the floating-point data 1 to 8, the sequencer 410 issues a request DC_W signal for writing fixed-point data to the rendering processor 500, and confirms that the fixed-point data has been received from the rendering processor 500. When the signal RP_ACC representing the graphic data is returned, the signal DC_ACC representing the reception of the graphic data is output to the geometry processor 50.

The sequencer 410 receives the floating-point data 1 to 8 while the counter circuit 42
From 0, when an instruction to return to the state receiving the command code is received, the state transits to a state receiving the command code, and when not received, the state of receiving the floating point data 1 to 8 is returned. Repeat the operation.

Here, counter circuit 420 outputs an instruction to return to a state in which the command code has been received, as follows.

As described above, the LEN register 430 is a register for storing the number of transfers in the command code. The LEN register 430 stores the number of transfers in the command code in accordance with an instruction from the sequencer 410 to set the number of transfers in the command code. Circuit 42
Output to 0. The counter circuit 420 includes a CNT register and a comparator. The CNT register is
When the initialization instruction is received from, the value of the register is initialized to 0, and the value of the CNT register is given to the scale factor unit 300.
When the signal RP_ACC, which has received the rendering data fixed-point data, returns from the rendering processor 500 while the sequencer 410 receives the floating-point data 1 to 8, the value of the CNT register is incremented.
The comparator compares the incremented value of the CNT register with the value of the LEN register, and when the value of the CNT register matches the value of the LEN register, instructs the sequencer 410 to return to a state in which the command code is received. give.

Next, FIG. 6 shows the configuration of the scale factor section 300.

As shown, the scale factor section 300
Are the registers S1 311, S2 312, S3313, S4 314, S5
315, S6 316, S7 317, S8 318 and a selector.

Registers S1 311 to S8 318 are registers for holding a scale factor corresponding to each of floating point data 1 to 8, and are supplied from the geometry processor 50 upon receiving a write instruction SET signal from the control unit 400. The bit scale data is distributed and written in units of 4 bits.

The selector 320 is connected to the registers S1 311 to S8
The counter value input from the control unit 400 with the value of 318
One is selected by the CNT signal and output to the format converter 200. Thereby, a corresponding scale factor can be given to the format conversion unit 200 for each of the floating point data 1 to 8 of the graphic data.

Next, FIG. 7 shows the configuration of the format conversion section 200.

As shown, the format conversion unit 200
Is an exponent processing unit 210 that calculates the shift amount from the scale factor and the exponent of the floating-point number, and a mantissa shift unit 23 that right-shifts the mantissa of the floating-point number and converts it to a positive fixed-point number.
If the sign of the floating-point number is minus, the sign processing unit 250 converts the positive fixed-point number obtained by the mantissa shift unit into a negative fixed-point number.

The exponent processing section 210 includes a scale factor section 300
, The value of the scale factor output from, and the exponent of the floating-point number are added, the offset value of 127 is subtracted from the addition result to perform offset correction, and only the lower 5 bits are extracted from the data subjected to the offset correction. By performing bit inversion, the shift amount of the mantissa shift unit 230 is obtained.

Here, the reason why the offset value of 127 is subtracted from the result of addition is that 127 is added to the exponent of the floating-point number according to the IEEE standard. The reason why only the lower 5 bits are extracted is that only a 5-bit information is required for the shift amount in order to convert to a 32-bit fixed-point number. The bit inversion is performed to convert the value of the exponent from left shift to right shift.

If the value obtained by adding the value of the scale factor output from the scale factor unit 300 and the exponent of the floating-point number is less than the constant 127, the exponent processing unit 210
Since the value cannot be expressed too small even if it is converted to a 32-bit fixed-point number, a process of outputting an instruction to clamp the data of the fixed-point number to 0 to the sign processing unit 250 is also performed.

Next, the mantissa shift unit 230 inserts 1 in the most significant bit, and places the mantissa 23 of the floating-point number in bits 30 to 8.
A 32-bit coefficient is calculated by inserting bits and setting bits 7 to 0 to 0, and the 32-bit coefficient is calculated by the exponent processing unit 210.
Performs a right shift by the shift amount obtained by the above, and converts it into a positive fixed-point number. The reason why 1 is inserted into the most significant bit of the 32-bit coefficient is that the most significant 1 of the mantissa is omitted in the IEEE standard.

Next, if the sign of the floating-point number is minus, the sign processing unit 250 converts the positive fixed-point data obtained by the mantissa shift unit 230 into negative fixed-point data. , The fixed-point data is set to 0, and the fixed-point data is passed to the rendering processor 500.

Here, an example of converting a floating-point number of 2.625 to a fixed-point number having a decimal part of 3 bits will be described below.

The floating point number of 2.625 has a sign bit
(0) ₂ , exponent (10000000) ₂ , mantissa (01
11000000000000000000000) ₂ .

When the exponent processing unit 210 adds the bit position of the decimal point and the exponent, it becomes (10000011) ₂ , and 12
When the offset correction is performed by subtracting 7, (00000010)
0) It becomes ₂ .

Then, when the lower 5 bits are extracted (0
0100) ₂ and performing bit inversion (1101)
1) It becomes ₂ and the shift amount becomes 27.

The 32-bit coefficient of the mantissa shift unit 230 is
(10101000000000000000000000
00000000) ₂ and this is shifted right by 27 bits to obtain (00000000000000000000000)
000000010101) ₂ and a positive fixed-point number can be obtained.

The lower 4 bits or more as an integer part indicate 2 and the lower 3 bits as a decimal part indicate 0.625.

In the sign processing unit 250, the sign bit is (0) ₂
Because it indicates positive, the rendering processor 500 does not convert the positive fixed-point number to a negative fixed-point number.
Pass to.

The first embodiment of the graphics processing apparatus according to the present invention has been described above.

Hereinafter, a second embodiment of the graphics processing apparatus according to the present invention will be described.

The overall configuration of the graphic processing apparatus according to the second embodiment is the same as the configuration shown in FIG. 1 and can be applied to a computer as shown in FIG.

FIG. 8 shows graphic data input from the geometry processor 50 to the data converter 100 and drawing data output from the data converter 100 to the rendering processor 500 in the second embodiment.

As shown in the figure, the graphic data of the second embodiment differs from the first embodiment in that the data converter 100
The scale data is omitted from the graphic data input from the geometry processor 50 in FIG.

Next, FIG. 9 shows an input / output data format of the data converter 100.

As shown, the formats of floating point data, fixed point data, and command data are the same as those described in the first embodiment.

The configuration of the graphic data output from the geometry processor 50 can be specified from the operation code of the command code.

For example, if the operation code is (0
001) In the case of ₂ , this means a command for drawing a straight line. In this case, floating point data 1 to 7 are
It is determined that a starting point X, Y coordinate, an ending point X, Y coordinate, and luminances R, G, B are indicated. In the case of (0010) ₂ ,
This means a command for drawing a triangle. On the other hand, it is determined that floating point data 1 to 5 indicate vertices X, Y coordinates, and luminances R, G, and B. In addition,
When displaying one triangle on the CRT 700, the figure data of the triangle is given to the rendering processor 500 three times.

As described above, for the value of the operation code, the type of each floating-point data following the command code including the operation code is determined. Therefore, in the second embodiment, in the data converter 100, for example, when the operation code is (0001) ₂ , the starting point X coordinate of the floating-point data 1 is set to 3
Conversion to fixed-point data 1 located at the bit position
If the Y coordinate of the floating point data 2 starting point is converted to fixed point data 2 whose decimal point is located at the second bit from the least significant bit, and the operation code is (0010) ₂ ,
Floating point data 1 vertex X coordinate is 4 from the lowest decimal point
Conversion to fixed-point data 1 located at the bit position
Floating point data 2 Vertex Y coordinate is 2 from the lowest decimal point
According to the operation code and the position of the floating-point data, the bit position of the decimal point of the fixed-point data to be converted from the floating-point data is set in advance according to the operation code and the position of the floating-point data. By determining according to the correspondence, each floating-point data is converted into a fixed-point number having a bit position of a decimal point according to the type of the data without receiving scale data from the geometry processor unit 50 as in the first embodiment. I do.

Hereinafter, details of the data converter 100 for performing such conversion will be described. The overall configuration of the data converter 100 is the same as that shown in FIG. 1, and includes a control unit 400, a scale factor unit 300, and a format conversion unit 200.

FIG. 10 shows the configuration of the control unit 400.

As shown, the control unit 400 includes:
A sequencer 415 for managing the state of the data converter 100 and controlling the transfer of graphics and drawing data to the geometry processor 50 and the rendering processor 500, and a counter circuit 420 for managing the number of data to be passed to the rendering processor 500; The transfer number lookup table 435 detects the transfer number in the command code from the operation code.

The state managed by the sequencer 415 includes a state where the data converter receives a command code from the geometry processor 50 and a state where the data converter receives floating point data 1 to 8.

When the sequencer 415 receives the command code, the sequencer 415 stores the operation code of the command code in the COM register, outputs the content of the operation code to the transfer number lookup table 435, and sends the contents of the CNT register to the counter circuit 420. It issues an initialization instruction, issues a drawing data command code write request DC_W signal to the rendering processor 500, and passes the command code to the rendering processor 500. When a signal RP_ACC indicating that the drawing data command code has been received from the rendering processor 500 is returned, the signal DC_A indicating that the graphic data has been received is received by the geometry processor 50.
A CC signal is issued, and the state changes to a state receiving floating point data 1 to 8.

Next, while receiving the floating point data 1 to 8, the sequencer 415
When the value of the COM register in which the operation code is stored is given to 00, a request DC_W signal for writing fixed-point data is issued to the rendering processor 500, and a signal RP_ACC indicating that fixed-point data has been received is returned from the rendering processor 500. , A signal DC indicating that the floating point data has been received by the geometry processor 50
Issue the _ACC signal. When receiving an instruction to return to a state where a command code is received from the counter circuit 420 while receiving the floating-point data 1 to 8, the sequencer 415 transitions to a state where the command code is received. Otherwise, the operation of receiving the above floating point data 1 to 8 is repeated.

In the transfer number lookup table 435, the value of the transfer number of the fixed-point data is registered from L1 to L16 for each operation code, and one of the values is registered in the COM register output from the sequencer 415. Is selected by the selector 436 in accordance with the value of.

For example, when the transfer number 7 is registered in L1 and the transfer number 5 is registered in L2, and the value operation code of the COM register is (0001) ₂ , the transfer number 7 is counted by the counter circuit 420.
When the value of the COM register is (0010) ₂ , the transfer number 5 is given.

The counter circuit 420 comprises a CNT register and a comparator. The CNT register is the sequencer 415
When the initialization instruction is received from, the value of the register is initialized to 0, and the value of the CNT register is given to the scale factor unit 300.
In a state where the sequencer 415 is receiving the floating point data 1 to 8, when the signal RP_ACC signal receiving the drawing data fixed point data is returned from the rendering processor 500, the value of the CNT register is incremented.
Then, the comparator compares the incremented value of the CNT register with the number of transfers transmitted from the transfer number lookup table 435, and if the values match, returns to the state in which the sequencer 415 has received the command code. Give instructions.

FIG. 11 shows the configuration of the scale factor section 300.

The scale factor section 300 has a table for registering scale factors from Scale1 to Scale16 for each operation code.

One of the plurality of scale factors stored in the Scale1 table is selected by the selector 341 in accordance with the value COM signal of the COM register output from the control unit 400.
Is selected and output to the selector 360. Scale
Similarly, the scale factor corresponding to the value COM signal of the COM register is selected one by one from 2 to Scale16.
The data is output to the selector 360.

Next, the Sc selected by each of the selectors 341 to 356
Each numerical value from ale1 to Scale16 is selected one by one by the selector 360 by a counter value CNT signal input from the control unit and output to the format conversion unit 200. Thereby, a corresponding scale factor can be given to the format conversion unit 200 for each of the floating point data 1 to 8 of the graphic data.

The format converter 200 is the same as the format converter 200 of the first embodiment described above.

The second embodiment of the present invention has been described above.

In the second embodiment, the contents of the transfer number lookup tables L1 to L16 storing the transfer numbers determined corresponding to the operation codes and the scale factor tables S1 to S16 are, for example, as shown in FIG. CPU10
Alternatively, an arbitrary value may be set from the geometry processor 50. By doing so, it is possible to appropriately change the format of the graphic data.

Hereinafter, a third embodiment of the present invention will be described.

The third embodiment is different from the graphic processing device according to the first embodiment in that the data converter 100
It is provided with a function of passing floating point data to the rendering processor 500 in a format as received from the geometry processor 50 without converting the data to fixed point data.

Such a function is used when there is data to be processed as floating-point data even in the rendering processor 500 or, as shown in FIG. 12, if only floating-point data is included in data following the command code as operation data. However, when a format in which data including a command code is present is adopted, it is effective to pass such data to the rendering processor 500 as it is.

FIG. 13 shows the format of the command data in this case.

As shown in FIG. 13, in the third embodiment, a conversion control code indicating data that is not converted to a fixed point is added to other control codes following the operation code of the command code.

In the figure, (00100000) ₂ indicates the position of the value (1) ₂ , that is, the third data from the front is not converted into fixed-point data by the data converter 100 and is directly transmitted to the rendering processor 500. Indicates what should be output.

Hereinafter, the data converter 10 according to the present embodiment will be described.
0 will be described.

The overall configuration of the data converter 100 is the same as that shown in FIG.
Scale factor unit 300, format conversion unit 200
It is composed of The control unit 400 and the scale factor unit 300 may be the same as those described in the first embodiment.

FIG. 14 shows the remaining format converter 200.
Is shown.

As shown in the figure, the format converter 210 according to the present embodiment is obtained by adding a control code processor 290 and a selector 291 to the configuration of the format converter 200 shown in FIG.

The control code register in the control code processing section 290 stores the sequencer 410 of the control section 400.
Is in the state of receiving the command code, the conversion control code in the other control codes in the command code is stored.

The control code processing unit 290 controls the selector 291 so that the selector 291 normally selects the fixed-point data output from the code processing unit 250. The value output from the counter circuit 420 of the control unit 400 is , The value of the position indicating that the conversion control code stored in the register does not convert data (the conversion control code is (001)
00001) If ₂ and 3 and 8), the selector 291 controls the selector 291 so as to select the fixed-point data received from the geometry processor 50.

As described above, the third embodiment of the present invention has been described.

In the graphics processing apparatus described in the second embodiment, the format conversion unit 200 of the data converter 100 is configured as shown in FIG. It can be applied to the second embodiment in the same way as the application to the embodiment.

According to each of the embodiments described above, the data converter 100 is provided between the geometry processor 50 and the rendering processor 500, and the processing of the geometry processor 10 and the floating-point data are converted to the fixed-point data in a pipeline manner. Since the conversion is performed, high-speed graphics processing can be performed. In addition, since the bit position of the decimal point can be arbitrarily controlled for each data type, and conversion from a floating-point number to a fixed-point number can not be performed, it is possible to deal with a wide variety of data.

[0111]

As described above, according to the present invention, it is possible to provide a graphics processing apparatus capable of reducing a reduction in processing speed required for converting a floating-point number to a fixed-point number. .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a graphics processing device.

FIG. 2 is a block diagram illustrating a configuration of a computer to which the graphics processing device is applied.

FIG. 3 is a diagram showing input / output data of a data converter according to the first embodiment of the present invention.

FIG. 4 is a diagram showing an input / output data format of the data converter according to the first embodiment of the present invention.

FIG. 5 is a block diagram illustrating a configuration of a control unit according to the first embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration of a scale factor unit according to the first embodiment of the present invention.

FIG. 7 is a block diagram illustrating a configuration of a format conversion unit according to the first embodiment of the present invention.

FIG. 8 is a diagram showing input / output data of a data converter according to a second embodiment of the present invention.

FIG. 9 is a diagram showing an input / output data format of a data converter according to a second embodiment of the present invention.

FIG. 10 is a block diagram illustrating a configuration of a control unit according to a second embodiment of the present invention.

FIG. 11 is a block diagram illustrating a configuration of a scale factor unit according to a second embodiment of the present invention.

FIG. 12 is a diagram showing input / output data of a data converter according to a third embodiment of the present invention.

FIG. 13 is a diagram showing a format of command data according to a third embodiment of the present invention.

FIG. 14 is a block diagram illustrating a configuration of a format conversion unit according to a third embodiment of the present invention.

[Explanation of symbols]

10 ... CPU, 50 ... Geometry processor, 100 ...
・ Data converter, 200 ・ ・ ・ Format converter, 210 ・
..Exponent processing section, 230 ... Mantissa shift section, 250 ... Sign processing section, 290 ... Control code processing section, 291 ...
・ Selector, 300 ・ ・ ・ Scale factor part, 311-318
... Registers S1-S8, 320 ... Selector, 341-356
... selector, 360 ... selector. 400 ... Control unit, 410 ... Sequencer, 415 ... Sequencer, 435 ... Transfer number lookup table, 436 ...
Selector, 420 ・ ・ ・ Counter circuit, 430 ・ ・ ・ LEN register, 500 ・ ・ ・ Render rig processor, 600 ・ ・ ・ Frame memory, 700 ・ ・ ・ CRT,

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Katsunori Suzuki 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi, Ltd. (72) Kazunori Oniki 5-2, Omikamachi, Hitachi City, Ibaraki Prefecture No. 1 Inside the Omika Plant of Hitachi, Ltd.

Claims (6)

[Claims] 1. A processor for outputting graphic data including a floating-point data string representing information for specifying a graphic to be drawn in a floating-point format, and fixed-point data representing the contents of the graphic to be drawn in a fixed-point format A rendering unit that expands a graphic into pixels in accordance with drawing data including columns and outputs the result.The floating-point data included in the graphic data output by the processor is converted into fixed-point data. A data converter that outputs the drawing data to the rendering unit, wherein the data converter has a decimal point position changing unit that changes a bit position of a decimal point of the fixed point data for converting floating point data. Graphics processing device. 2. A graphics processing apparatus according to claim 1, wherein said processor includes, as said graphic data, decimal point bits of fixed-point data to be converted with respect to each floating-point data string together with said floating-point data sequence. The scale factor data specifying the position is output, and the decimal point position changing means of the data converter outputs the bit position of the decimal point of the fixed-point data for converting each floating-point data, for the floating-point data, the processor outputs A graphics processing apparatus, wherein a bit position of a decimal point specified by scale factor data included in the graphic data is set. 3. The graphics processing apparatus according to claim 1, wherein the processor outputs, as the graphic data, a command representing a type of a graphic specified by the floating-point data string, together with the floating-point data string. The data converter includes a scale factor table that stores a bit position of a decimal point of the fixed-point data for converting each floating-point data included in the graphic data for each of the commands. The decimal point position changing means stores the bit position of the decimal point of the fixed point data for converting each floating point data in the scale factor table corresponding to the command included in the same graphic data as the floating point data. A graphics processing device characterized by a bit position of a decimal point. 4. The graphics device according to claim 3, wherein the scale factor table of the data converter stores a floating point bit position of fixed point data for converting each floating point data included in the graphic data. A scale factor table for storing the position of the decimal point data in the graphic data and the command corresponding to each of the commands; The position is a bit position of a decimal point stored in the scale factor table corresponding to the command included in the same graphic data as the floating point data and the position of the floating point data in the graphic data. Graphics processing unit. 5. The graphics processing apparatus according to claim 2, wherein the processor is configured to generate, as the graphic data, floating-point data included in the floating-point data string together with the floating-point data string. Among them, a control code that specifies floating-point data that is not converted to fixed-point data is output, and the data converter does not convert floating-point data specified by the control code output by the processor to fixed-point data, A graphics processing device, which is included in drawing data and outputs to the rendering unit. 6. The graphics processing device according to claim 1, 2, 3, 4, or 5, a frame memory for storing pixels output by rendering the graphic by the rendering unit, and a frame memory stored in the frame memory. And a display device for sequentially reading and displaying each pixel.