JPS6177089A - Display control system - 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] The present invention relates to a scroll display control method.

[Prior art]

Conventionally, when the contents of a memory MEM that stores information to be displayed are displayed on a CRT, the information on the screen of the CRT can be smoothly scrolled in the horizontal direction (in units of one dot) as follows. A controller (not shown) specifies the display start address of the memory MEM, and its contents are read from the memory MEM and loaded into the register ρiSO. The contents stored in register PiSO are stored in register PiSO by serial shifting.

The contents of register 5iPO are input to selector SEL in parallel. Selector SEL sends one of the contents of register 5iPO to the CRT according to the contents of register REG.

The data (parallel) in the memory MEM is changed to serial data using the register PiSO, and the contents of the register 5iPO are sequentially transferred from the beginning to the CRT using the selector SEL, so that the contents of the memory MEM are displayed on the CRT. However, with selector SEL
The screen is shifted to the left by transmitting the control sent to the RT to the CRT, for example, by the desired amount (in dot units) of data that is later than the data to be shifted to the left.

Conventionally, this type of display device can achieve bit-by-bit smoothness in both the vertical and horizontal directions by specifying the display start address of the CRT controller and the scroll value SD of the bit-by-bit smooth scroll circuit consisting of the serial-parallel conversion register 5iPO and the data selector SEL. Since it was configured to allow scrolling, it was not possible to divide the display screen and scroll each divided screen because the entire screen was displayed simultaneously.

〔the purpose〕

The present invention provides a display control method that makes it possible to independently specify a scroll value for each divided screen and to perform scrolling independently.

〔Example〕

FIG. 3 is a block diagram illustrating an embodiment according to the present invention. In this figure, the same parts as in FIG. 1 are given the same reference numerals.

In this embodiment, an example will be explained in which the screen is divided into two parts as shown in FIG. 2, and each part is scrolled independently.

REG l is a register that specifies the dividing position, and RE
G2 and REG3 are registers that store scroll values for each divided screen.

C0tlNT is a counter that counts the division value, loads the contents of register REG 1 every VSYNC:, and
SYNCC line). When the counter value reaches (COUNT=O), the flip-flop F
Set F. Register REG2 when FF=1.

Switch 3. The flip-flop FF is cleared and initialized by VSYNC.

SEL is a selector, and R is the signal of flip-flop FF.
Outputs EG1 or REG2.

The operation of the embodiment configured as described above will be explained.

The contents of the register REGI contain the value of X when the screen is divided at the X-th line from the top.

The settings of each register are specified by instructions from a controller that controls the entire system.

The divided value is input to the register REG 1 via the data bus DATA Bus, and the position determined by, for example, a cursor (cursor counter) is input to the register REGI.

Registers REG 1 and REG2 are entered into the registers by using the scroll keys on the keyboard.

The register REG1 is loaded with a division value, for example, X every VSYNC, and is counted and grounded by HSYNC.

During that time, flip-flop FF is in the reset state, so the contents of register REG2 are
is applied to the screen 1, and the screen 1 is scrolled by the register REG2.

On the other hand, when the counter reaches X, that is, 0, carry CA
is output, and the flip-flop FF is set.

Therefore, selector SEL selects registers REG2 to REG.
3, and this time the register REG3 scrolls, that is, the screen 2 is scrolled.

In the present invention, it is divided into two, but by using N counters and scroll values (REG2.3) for each division, N
It is easy to deal with division.

〔effect〕

The display screen is divided, one screen is set as a menu (command) screen, the other screen is set as a normal display screen, and only the display contents can be scrolled by instructions from the software, thereby achieving a smooth scrolling function. In the conventional example, this cannot be achieved without moving the display MEM data using software, and the processing speed can be improved.

[Brief explanation of drawings]

FIG. 1 is a conventional display control block diagram. Figure 2 is a diagram explaining the split screen, FIG. 3 is a block diagram according to the present invention. RE　G　1------Register RE　G　2-=-register RE　G　3---1-Register COUNT---Counter SEL ----- Selector 3rd yen

Claims (1)

[Claims] A display control method, in a display device capable of dividing a display screen, that has means for storing a scroll value for each divided screen.