STV9432TAP

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11 - SOFTWARE RESET REGISTER

This bit will be automatically reset by the device.

Software Reset will put all Write registers at their default power-on value, and reset all internal logic

12 - ON-SCREEN DISPLAY

The STV9432TAP on-screen display is able to dis-

play any line of characters (character strip) any-

where in the screen.

Character strings are programmed by the MCU in

the internal ROM font. Character strips may be

adjacent or separated by vertical spaces (Spacing

strips)

Consequently, one display page is made of a list

of Character strips and Spacing strips.

A Top Margin and a Left Margin are programmable

in dedicated registers.

12.1 - RAM PROGRAMMING

12.1.1 - Two kinds of Data

Strip Descriptors and Character Codes

An OSD screen is made of a number of Character

and Spacing strips.

There are two groups of Data that make one OSD

screen:

- a Strip Descriptors list,

- Text strings - one per Character strip.

Each Strip is associated with a 2 bytes Strip

Descriptor.

There are two kinds of Strip Descriptors:

- Character Strip Descriptors: they contain the

Text string Ram address of the Character Strip,

- Spacing Strip Descriptors: they specify the ver-

tical space height.

In the example shown in Figure 9, the OSD

screen, is made of 9 strips.

In RAM, there is:

- one list of 9 Strip descriptors

(size = 9 x 2 bytes = 18 bytes),

- 6 Text strings, each of them is made of the

character codes of the line of text.

Text strings can be programmed anywhere in

RAM. The Descriptor list can be located at 16 dif-

ferent addresses in RAM, this address is defined

in the Display Control Register.

It is consequently possible to store up to 16 differ-

ent pages in RAM.

The current Displayed page is specified in the Dis-

play Control Register. It refers to a given Page

Descriptor list.

Figure 9. Display Page: list of Character and Spacing strips

403F

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-

-

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-

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RST

TOP MARGIN

Text line number one

Text line number two

Text line number three

Text line number four

Text line number five

Text line number six

Strip 1 : Character Strip

Strip 2 : Character Strip

Strip 3 : Spacing Strip

Strip 4 : Character Strip

Strip 5 : Spacing Strip

Strip 6 : Character Strip

Strip 7 : Character Strip

Strip 8 : Character Strip

Strip 9 : Spacing Strip (Bottom Margin)