JPS58137886A - Cursor control circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cursor control circuit used in a CRT display device having a kanji display function.

[Technical background of the invention and its problems]

A CIT display with a kanji display function using a CRT controller (hereinafter referred to as CRTC-LSI). In the Ray device, a cursor control circuit as shown in Fig. 1 is used. In response to the unit black signal ANK-CLK, a cursor signal (hereinafter referred to as ANK cursor signal) in units of melon characters is generated in accordance with this black signal ANK-CU.
1 that outputs DISF and character address CA;
The A[cursor signal ANK-CUDI8P obtained from this CRTC-LSI 1a is inputted to the Kanji cursor generation circuit 1111C, and the general cursor signal ANK-CUDI
Kanji cursor signal K-CUDI8 with double width of I8P
P is generated. Furthermore, -CUDI8P is input to the kanji cursor signal outputted from this kanji cursor generation circuit 11, and I cursor signal A[-CUDI8P outputted from the above-mentioned CRTC-L8110 is inputted to the selection circuit 11FIC,
According to the control information CCK output from the cursor control memory IJ, one of the cursor signals (A
NK-CUDI8P/K-CUDI8P) are selectively output. The cursor signal outputted from the selection circuit 12 is sent to the CRT display section, and a cursor having the width of a melon character or a kanji character width twice that width is displayed at a designated position on the display screen.

In addition, in the cursor control memory 1zK, selection information of the cursor/kanji cursor is set in advance by the CPU in units of characters, and is read out by the character address C from the CRTC-LSI 10, and this information is used as control data. Select circuit J:IV as CC
C is supplied.

However, in such a conventional circuit configuration,
The following inconveniences occurred. In other words, in order to increase the resolution of the CRT display, if the operating frequency of the CRT display is increased, the CRTC-LSI
The clock signal ANK-CI! The frequency of C-LSI 1 is also high.
The generation cycle of the character address Cm outputted from 0, furthermore, the 7 letter (not shown), memory address, etc. is shortened. Accordingly, it is necessary to access the cursor control memory 11, refresh memory, etc. at high speed, but there is a limit to the cycle time of these memories, and the above-mentioned memories cannot be accessed beyond this limit. In this case, conventionally, as mentioned above, a black signal with a frequency of two characters is used, and α
- Based on the CRTC-LSI 10, the CUDI8F, character address CA, IJ fresh memory address, etc. are obtained from the cursor signal in character units based on the CRTC-LSI 10.

-Tsuru control memo 171 J, changed Kti97,
In many cases, the cycle time of the memory is already tight. Therefore, instead of the clock signal ANK-CLICIIc, which has a frequency in units of melon characters, a clock signal in units of kanji characters, which has half the frequency, is used as the CRTC.
- It is possible to supply LSI I II K to provide a margin for the cycle time of each memory, but in this case, the display of each melon cursor for the left half width and the right half width of the Kanji cursor, which is 172 widths, is possible. In addition, when the half-width shift kanji cursor and full-width kanji cursor are specified when the half-width shift kanji display function is provided, a cursor display selection means is required. Selection control means had not been realized.

[Purpose of the invention]

In the case where the frequency of the clock signal that is the generation source of cursor signals and character addresses, etc. is lowered from the frequency of ANK character units to the frequency of Kanji character units, each An object of the present invention is to provide a cursor control circuit that can specify the display of an α cursor and one or more types of kanji cursors with a relatively simple circuit configuration.

[Summary of the invention]

The present invention uses four clock signals with frequencies in units of ANK (alpha numeric) characters, and uses a clock signal with a frequency in units of Kanji characters as a clock signal for CRTC-L.
SI (1 piece 7' CRT controller) K supply,
The CB'rC-LSI generates a cursor signal (full-width kanji cursor signal) for each kanji character and a character address in accordance with this clock cycle. And this CRTC-LS I, the cursor signal that shows multiple outputs, and the C
Based on the RTC-LSI K supplied signal and K, the cursor signal generation circuit generates two types of cursor signals corresponding to the left half-width and right half-width of a full-width Kanji character,
Furthermore, a plurality of types of cursor signals including a half-width shift kanji cursor are obtained as necessary. Furthermore, multiple types of cursor signals obtained from Jin's cursor signal generation circuit are input to the cursor selection circuit, and according to the first control information, one of the trace cursors (left half-width/right half-width) and the kanji cursor (full-width/half-width shift) are input to the cursor selection circuit. ) is selected, and either the Kanji cursor/ANK cursor is selected according to the second control information. At this time, the first control information is seen from the tree, fflow, and f, which hold the control information sent from the host device (CPU), and the second control information is given from the cursor control memory. .

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Second
The figure is a circuit diagram showing an embodiment of the present invention. In the figure, 200 is a clock signal with a frequency of a melon character unit [-CLK is divided by 1/2 and the frequency of a kanji character unit is divided by 4 to obtain a signal K -CLK 1/2
It is a frequency divider. 201 receives the signal K-CLK obtained from the 172 frequency divider 200, and outputs the digital signal K-CLK.
CBTC-L8 I which generates the full-width kanji cursor signal KFCU and character address CA etc.
It is. The CRTC-L8I ffi 01 inputs and outputs various signals for display control in addition to the signals described above, but these are omitted here because they are not directly related to the present invention. 202 is citc-tar z a J
Full-width kanji cursor signals KFCυ and 172 that are output
The clock signal K-CLK output from the frequency divider 200
In response to the above full-width kanji cursor signal KFCU,
, half-width shift kanji cursor signal KHCU, cursor signal ANKCU corresponding to the left half of a full-width kanji character
(U) is a cursor signal generation circuit that generates an arc cursor signal ANKCU (L) corresponding to the left half of a full-width Kanji character. For example, a D-type frig 70ZZO (D F/F) that delays the full-width Kanji cursor signal KFCU by half a cycle of the K-CLK signal.
) Obtain the half-width shift kanji cursor signal KHCU and shift it to the full-width kanji cursor signal KFCU.

And dart (A
) Obtain the ρ■ cursor signal ANKCU (U) corresponding to the left half of the full-width kanji character, take the half-width shift kanji cursor signal KHCU, and AND gate (A) to AND the signal with -CLK. Cursor signal ff1cU (L) corresponds to the left half of a full-width kanji character.
get. 10B indicates various cursor signals (KFCU, KHCU) generated by the cursor signal generation circuit taX.
, ANKCU(U).

ANKCU (L)), the first control information (CCA) K, and one Kanji cursor signal (KF
CU/10Icu) and one cursor signal (
This is the first selector that simultaneously selects ANKCU(U)/ANICU(L)). A second selector 204 selects either one of the Kanji cursor signal and the A[cursor signal output from the first selector 203 according to the second control information (ccn)K. 2o5 constitutes the first storage section,
A D-type 7 that stores first control information for specifying the left half-width and right half-width corresponding to the half-width half-width of a full-width Kanji character, given by the host device (hereinafter referred to as CPU).
Lituzov IV, f. 20σ constitutes a second storage unit, which stores in advance the second control information for specifying the Kanji cursor/ANK cursor given by the CPU, and stores the character address C' output from the CRTC-LSI 201. AK] is a cursor control memory whose reading is controlled.

FIG. 3 shows an example of cursor display according to the various cursor signals shown in FIG.
Full-width kanji cursor according to Cυ, sex is cursor signal K
Half-width shift kanji cursor following HCU K, sex is ANK cursor following cursor signal ANKCU(U), 10
4 is a blank cursor that follows the cursor signal ANKCU(L)K.

FIGS. 4(a) to 4(g) are time charts showing the signals of each part in FIG. 2 above.

Here, the operation in one embodiment will be explained. A black signal with a frequency in units of ANK characters given by an external circuit,
The signal ANK -CLK (Fig. 4(a)) is divided by the 172 frequency divider 200, and the frequency of each Kanji character is divided into 4 signals -CLK (Fig. 4(b)).
is output as -CLK #1CRTC-LIiI to the clock signal output from this 172 frequency divider 200
j Oj, and is also supplied to the cursor signal generation circuit 101.

CRTC-L81! 01 is the character address OA based on the input signal or -CLK cycle.
and full-width kanji cursor signal KFCU (Figure 4(d))
Output. This full-width kanji cursor signal KFQ's black and red signals K-CLK and the cursor signal generation circuit 1
02. In the kernel signal generation circuit to2, C
When the full-width kanji cursor signal KFCU is received from the RTC-L81 j a 1, this signal is p, and the signal is K-C.
Based on LK and K, various cursor signals KFCU, CU, AN as shown in FIG. 4(d) to (g) are generated.
Outputs KCU(U) and ANKCtJ(L). The nine various cursor signals generated by this cursor signal generation circuit 202 are supplied to a first selector xexK, which selects one of the kanji cursor signals KFCU and 1KECU according to the contents of the first control information (OCA). On the other hand, the ANK cursor signal ANKCU(U), ANK
Either one of CU(L) is selected at the same time.

At this time, the first control information (OCA) is outputted, and the zth control information (CCII) is outputted from the t4 full control memory! 6gK holds control information given in advance by the CPU. Here, for example, fUyfflo, f2
Assuming that the content of 1Jl is "@0", indicating the left half-width designation of full-width kanji chu Yarakuta, this control information (O
CA = @O”), the first selector gos outputs a full-width kanji cursor signal KFCU in place of the kanji cursor signal, and outputs an ANK cursor signal ANKCU corresponding to the left half-width of a full-width kanji character as an ANK cursor signal. (υ) is output. Also, if the content of the 7th flop gos is @1" (ccm = 11"), indicating the right half-width specification of a full-width Kanji character, the first selector 20J , half-width shift kanji cursor signal KHC
U and cursor signal ANKCU (L) are selected and output. Then, one kanji cursor signal (KFCU/KHC) output from this first selector 203
U ) and one ANK cursor with a signal (ANKCU
(U)/ANICU(L)) is input to the second selector 204 together with the character address C output from the CRTC-L8I j 01, and is the second control information read out from the character control memory 206. (CCB), one of the cursor signals is selected. The cursor signal output from the second selector 204 is sent to the CRT display section and displayed at a designated cursor display position on the display screen. Various cursor signals at this time (KFCU/KHC
U/ANKCU':U)/AfiCU(L)
) An example of each cursor display according to K is shown in FIG.

In the above embodiment, various cursor signals (KFCU, KFCU,
KHCU, ANKCU(U), ANKCU(
Although the configuration is such that the selection of L)) is performed in stages between the first selector 203 and the second selector 104, it may be configured that the selection is performed by one selector circuit. Further, in the above embodiment, a cursor selection means including a half-width shift kanji cursor was taken as an example, but the cursor control circuit of the present invention can also be easily used in a CRT display device that does not have a display function of a half-width shift kanji cursor. . In this case, use the first selector 2oz to set α
Cursor signal (ANKCU([7) /ANKCU(L
) ) only need to be selected.

[Effects of the Invention] As described in detail above, according to the cursor control circuit of the present invention, the frequency of the p-tuk signal is changed from the frequency of the ANK character unit to the frequency of the Kanji character unit by controlling the generation source of the cursor signal and character address group. With a relatively simple circuit configuration, multiple types of cursors, including ANK cursors corresponding to the left half-width and right half-width of a full-width kanji character, can be displayed arbitrarily (with a relatively simple circuit configuration).

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a conventional cursor control circuit, and FIG. 2 is a circuit diagram showing an embodiment of the present invention.
Figure 3 is the above l! FIGS. 4(a) to 4(b) are time charts showing signals of various parts in the above embodiment. 200...1/2 frequency divider, 201...CRTC-L
SI (1ch, f CRT controller), 202...
・Tosol signal generation circuit, gos, se4・-selector,
gos...furi, gutsu a, f (first memory)
, xog... Cursor control memory (second storage section) Takehiko Suzue, Patent Attorney, Patent Attorney, Figure 1, 3, 2nd WJ, Figure 3 (a) ANK-CLK (9) ANKCU (L)

Claims (1)

[Claims] A display controller that receives a black signal with a frequency corresponding to a kanji character and outputs a full-width kanji cursor signal according to the frequency of the cursor signal, and a full-width kanji cursor signal and the cursor signal output from this display controller. A cursor signal generation circuit that generates a plurality of types of cursor signals including cursor signals based on alpha-2, -meri, and ku characters, and a first circuit that specifies the left half-width or right half-width corresponding to the half-width part of a full-width kanji character. a first storage section that stores control information for the cursor, and a second storage section that stores second control information that specifies whether the cursor to be displayed is displayed in units of kanji characters, mulberry characters, alpha-ni, -meri, or ku characters. and the above-mentioned No. 1. The first . A cursor selection circuit that selects one type of cursor No. 1 from a plurality of types of cursor signals generated by the cursor signal generation circuit based on second cursor control information. control circuit.