I.4.2 - Look-up Table Registers

Color look-up table [CLUT] is read/write RAM table.

Mapping address is described in Chapter I.3.2.

The CLUT is splitted in 2 blocks of 8 bytes. Each

byte contains foreground and background informa-

tions as described below :

SHA

BR

BG

BB

FL

FR

FG

FB

SHA

: Shadowing

FL

: Flashing foreground

BR, BG, BB : Background color

FR, FG, FB : Foreground color

If SHA = 1 and BR = BG = BB = 0, the background

of the character is transparent.

Each block may store a different set of colors. One

block of colors may be used for the normal items

of the menu while the second block, with brighter

colors, may be used for selected items of the menu.

The block selection is done by programming bit

CLU3 of CLU[3:0] of the character descriptor

(see Table 1). It remains selected all the row long.

Bit CLU2, CLU1 and CLU0 of CLU[3:0] of the

character descriptor select the active color at the

beginning of the row.

The active color can be changed along the row,

using 8 control codes COL0 to COL7.

Each control code (COL0 to COL7) active a dedicated

color byte in the CLUT as described in Table 2.

Table 1 : CLUT Block Selection

CLU3

CLU[2:0]

Code

Name

Ram

@(hex)

Reset Value

(hex)

0

0

Col 0

@3FE0

07

1

Col 1

@3FE1

16

2

Col 2

@3FE2

25

3

Col 3

@3FE3

34

4

Col 4

@3FE4

43

5

Col 5

@3FE5

52

6

Col 6

@3FE6

61

7

Col 7

@3FE7

70

1

0

Col 0

@3FE8

70

1

Col 1

@3FE9

61

2

Col 2

@3FEA

52

3

Col 3

@3FEB

43

4

Col 4

@3FEC

34

5

Col 5

@3FED

25

6

Col 6

@3FEE

16

7

Col 7

@3FEF

07

Table 2 : CLUT Color Selection

Code

Name

Code Nbr

(h)

Color Look-up Table in

RAM

COL1

10

@ 3FE0 : Color 0

COL2

11

@ 3FE1 : Color 1

COL6

16

@ 3FE6 : Color 6

COL7

17

@ 3FE7 : Color 7

COL0

10

@ 3FE8 : Color 8

COL1

11

@ 3FE9 : Color 9

COL6

16

@ 3FEE : Color 14

COL7

17

@ 3FEF : Color 15

I.4.3 - Control Registers

LINE DURATION (Reset Value : 20h)

3FF0 VSP HSP LD6

LD5

LD4

LD3

LD2

LD1

VSP

: V-SYNC active edge selection

= 0, falling egde,

= 1, rising edge.

HSP

: H-SYNC active edge selection

= 0, falling egde,

= 1, rising edge.

LD[6:1] : LINE DURATION

LD0 = 0

LD1 = 2 periods of character

One character period is 12 pixels long.

TOP MARGIN (Reset Value : 60h)

3FF1

M8

M7

M6

M5

M4

M3

M2

M1

M[8:1] : TOP MARGIN height from the VSYNC reference

edge.

M0 = 0

M1 = 2 scan lines

Note : The top margin is displayed before the first strip of descriptor

list. It can be black if FBK of DISPLAY CONTROL register is

set or transparent if FBK is clear.

HORIZONTAL DELAY (Reset Value : 20h)

3FF2 DD7 DD6 DD5 DD4 DD3 DD2 DD1 DD0

DD[7:0] : HORIZONTAL DISPLAY DELAY from the

HSYNC reference edge to the 1

of the character strips.

Unit = 6 pixel periods. Minimum value is 08h.

First pixel position = [DD[7:0] - 6] x 6 + 54.

with DD[7:0] = 1,3,5 then the delay is 60 pixel.

FUNCTIONAL DESCRIPTION (continued)

STV9427 - STV9428 - STV9429

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