FUNCTIONAL DESCRIPTION (continued)

I.3 - Addressing Space

STV9422/24registers, RAM and ROM are mapped

in a 16Kbytes addressing space. The mapping is

the following :

0000

1024 bytes RAM

Descriptors character

codes user definable

characters

03FF

0400

Empty Space

1FFF

2000

Character

Generator ROM

32FF

3300

Empty Space

3FFF

3FF0

Internal

Registers

3FFF

I.4 - Register Set

LINE DURATION

3FF0

VSP

HSP

LD5 LD4 LD3 LD2 LD1 LD0

*

0

0

1

11

111

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[5:0] : LINE DURATION

(number of pixel period per line divided

by 12 ie. Unit = 12 pixel periods).

HORIZONTAL DELAY

3FF1 DD7 DD6 DD5 DD4 DD3 DD2 DD1 DD0

*

000

01

000

DD[7:0] : HORIZONTAL DISPLAY DELAY from

the H-SYNC reference falling edge to

the 1

strips. Unit = 3 pixel periods.

CHARACTERS HEIGHT

3FF2

-

-

CH5 CH4 CH3 CH2 CH1 CH0

*

-

-

0

100

10

CH[5:0] : HEIGHT of the character strips in scan

lines. For each scan line, the number of

the slice which is displayed is given by :

SLICE-NUMBER =

round







SCAN

±LINE±NUMBER x 18

CH[5:0]







.

SCAN-LINE-NUMBER = Number of the

current scan line of the strip.

DISPLAY CONTROL

3FF3

OSD

FBK

FL1

FL0

-

P8

P7

P6

*

0

0

0

0

-

000

OSD

: ON/OFF (if 0, R, G, B and FBLK are 0).

FBK

: Fast blanking control :

= 1 : FBLK = 1, forcing black where these

is no display,

= 0 : FBLK is active only during character

display.

FL[1:0] : Flashing mode :

- 00 : No flashing. The character

attribute is ignored,

- 01 : 1/1 flashing (a duty cycle = 50%),

- 10 : 1/3 flashing,

- 11 : 3/1 flashing.

P[8:6]

: Address of the 1

current displayed pages.

P[13:9] and P[5:0] = 0 ; up to 8 different

pages can be stored in the RAM.

LOCKING CONDITION TIME CONSTANT

3FF4

FR

AS2

AS1

AS0

-

BS2

BS1

BS0

*

0

0

1

0

-

010

FR

: Free Running ; if = 1 PLL is disabled and

the pixel frequency keeps its last value.

AS[2:0] : P h a s e c o ns t an t dur i n g l oc k in g

conditions.

BS[2:0] : Frequency constant during locking

conditions.

CAPTURE PROCESS TIME CONSTANT

3FF5

-

AF2

AF1

AF0

-

BF2

BF1

BF0

*

-

0

1

1

-

011

AF[2:0] : Phase constant during the capture

process.

BF[2:0] : Frequency constant during the capture

process.

INITIAL PIXEL PERIOD

3FF6 PP7

PP6

PP5

PP4

PP3 PP2

PP1 PP0

*

0

010

1

000

PP[7:0] : Value to initialize the pixel period of the

PLL.

FREQUENCY MULTIPLIER

3FF7

-

-

-

-

FM3 FM2 FM1 FM0

*

-

-

--1

0

1

0

FM[3:0] : Frequency multiplier of the crystal

frequency to reach the high frequency

used by the PLL to derive the pixel

frequency.

STV9422 - STV9424

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