19

SCREEN CHARACTER and PATTERN DISPLAY CONTROLLERS

M35060-XXXSP

MITSUBISHI MICROCOMPUTERS

5. Scroll display mode

The scroll display mode is entered by setting registers SBIT0 to 3

(SA), SLIN0 to 4 (SB), SST0 to 4 (SC), and SEND0 to 4 (SD) (all

The screen is scrolled in the range from the (SC)’th line to the

(SD-1)’th line, and sections above and below this range are fixed.

The beginning line and beginning dot of scroll are the (SA)’th dot

on the (SB)’th line.

The screen can be scrolled up or down by successively

incrementing or decrementing SA and SB.

Figure 6 shows examples of how the display is scrolled. The scroll

range in these examples contains 12 lines (second to the 13th lines).

However, the screen can display only 11 lines at a time, and the

remaining one line is handled as a dummy line and not displayed.

< fixed block >

<

< fixed block >

Zero line

1st line

3rd

4th line

5th line

< fixed block >

< fixed block >

< Scrolling block >

2nd line (0 dot to 12 dots)

Setting example 1

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Fig. 6 Scrolling example

SA = 0

SB = 2

SC = 2

SD = 14

Line number when

on screen display

Setting example 2

SA = 3

SB = 5

SC = 2

SD = 14

Line number when

on screen display

6th line

7th line

8th line

10th line

11th line

12th line (0 dot to 12 dots)

9th line

14th line

15th line

16th line

Dummy line

13th line (0 dot to 12 dots)

Zero line

1st line

5th line (3 dots to 12 dots)

6th line

7th line

8th line

10th line

11th line

12th line

13th line

9th line

3rd line

2nd line

4th line (0 dot to 2 dots)

14th line

15th line

16th line

Dummy line

5th line (0 dot to 2 dots)

or

4th line (3 dots to 12 dots)

When displayed in order of SA = 0, 1, 2, and so on, the screen scrolls up. When displayed in order of SA = 12, 11, 10, and so on, the

screen scrolls down.

(1) To scroll the screen up, write the dummy line after you set the 0th dot in SA but before setting the 1st dot.

(2) To scroll the screen down, write the dummy line after you set the 0th dot in SA but before setting the 12th dot of the preceding line.