FUNCTIONAL DESCRIPTION (continued)

After the falling edge on V-SYNC, the first strip

descriptor is read at the top of the current table of

descriptors at the address given by P[9:0] (see

DISPLAY CONTROL register).I

f it is a spacing strip, SL[7:0] black or transparent

scan lines are displayed.

If it is a character strip, during CH[5:0] x (I + ZY)

scan lines (CH[5:0] given by the CHARACTER

HEIGHT register), the character codes are read at

the addressesstarting from the 1

descriptor until a end of line character or the end of

the scan line.

The next descriptor is then read and the same

process is repeated until the next falling edge on

V-SYNC.

CS D FBK FL[1:0]

P 8

P 7

P 8

DISP LAY CONTROL Re giste r

TABLE OF THE

DES CRIPTORS

2nd CHARACTER

STRIP CODES

OTHER

TABLE OF

DES CRIPTORS

OTHER

(UDC for e xa mple)

1st CHARACTE R

STRIP CODES

3rd CHARACTER

S RTIP CODES

OTHER

(CODES OR

DES CRIPTORS )

SP ACING

ROW1

ROW2

SP ACING

ROW3

SP ACING

RAM CODE

AND DES CRIPTORS

V-SYNC

TOP SP ACING S TRIP

1s t CHARACTER S TRIP

2n d CHARAC TER S TRIP

3rd CHARACTER S TRIP

SPACING STRIP

|

BOTTOM S P ACING S TRIP

S CREEN

Figure 7 : Relation between Screen/Address Page/Character Code in RAM

Slice 18 of the character n

°2

only for vertical shadowing

(not displayed).

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

12

3

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

45

6

36 Pixels (= 3 Characters)

Character Number

Character Number

ON THE SCREEN

(example for Character n

°5)

IN THE RAM

Slice 0

Slice 1

Slice 2

Slice 3

Slice 4

Slice 5

Slice 6

Slice 7

Slice 8

Slice 9

Slice 10

Slice 11

Slice 12

Slice 13

Slice 14

Slice 15

Slice 16

Slice 17

Slice 18

: 0x01

: 0x00

: 0x08

: 0x0c

: 0x0e

: 0x0f

: 0x0f

: 0x0f

: 0x0f

: 0x0e

: 0x0c

: 0x00

: 0x00

: 0x00

: 0x00

: 0x00

: 0x00

: 0x00

: 0x00

0xff =

0xff

0x7f

0x3f

0x1f

0x1f

0x1f

0x1e

0x1e

0x3c

0x3c

0x78

0x78

0xf1

0x00

0x00

0x00

0x00

0x00

Odd

Address

Even

Address

Figure 8 : User Definable Character

STV9425 - STV9425B - STV9426

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