ST6388 datasheet(58/82 Pages) STMICROELECTRONICS

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ST6380, ST6381, ST6382, ST6383, ST6388, ST6389

ON-SCREEN DISPLAY (Cont’d)

The VSYNC pin may alternatively be sampled by

software in order to know the status; this can be

done by reading bit 4 of register E4h; this bit is in-

verted with respect to the VSYNC pin.

6- The OSD oscillator external network should

consist of a capacitor on each of the OSD oscilla-

tor pins to ground together with an inductance be-

tween pins. The user should select the two capac-

itors to be the same value (15pF to 25pF each is

recommended). The inductance is chosen to give

the desired OSD oscillator frequency for the appli-

cation (typically 56

µH).

4.9 MIRROR REGISTER

This an 8-bits Register at address DEh. It is unde-

fined on Reset. After writing, the read value is the

reversed byte:

Bit0->Bit7, Bit1->Bit6, Bit2->Bit5, Bit3->Bit4,

Bit4->Bit3, Bit5->Bit2, Bit6->Bit1, Bit7->Bit0

Note: Writing the XOR register affects the value of

this register.

4.10 XOR REGISTER

This an 8-bits Register at address DFh. It is unde-

fined on Reset. To compute the XOR of two 8-bits

values, the user has to write the first value in the

MIRROR register (DEh) and then the second val-

ue in the XOR register (DFh). After that the XOR

result can be read from the XOR register.

To compute a new XOR with the result of the pre-

vious operation, the user can directly write the sec-

ond value in the XOR register and read the XOR

result in this same register.

Note: writing the XOR register affects the value of

the MIRROR register also.

ST6388 Datasheet(PDF) 58 Page - STMicroelectronics