Sensoray 614 Caption Overlay User Manual

Page 18

Caption/Overlay Window Formation and Data Loading

Each window (field) of Caption/Overlay is formed with a series of selected
caption character or overlay bitmap-block selection # + their attributes (including
transparent mode and color selection). It’s aligned like following for each
window/field:

Selected Char/bmBlk Attribute (Transp+Y[2:0]+U[2:0]+V[2:0]) + Char/bmBlk#[5:0]

Last Selected Char/bmBlk Attribute (Transp+Y[2:0]+U[2:0]+V[2:0]) + Char/bmBlk#[5:0]

Refer to the Section-II, for the details of attribute formation and char/bmBlk
selection.

For holding the window formation data, there are eight RAM blocks (in the 614
FPGA) designed for all eight windows/fields individually. Their base address
mapping is designed as following:

#define

G_CAPRAMATTR_1

0x0200

// Caption window #1 attr RAM base.

#define

G_CAPRAMATTR_2

0x0240

// Caption window #2 attr RAM base.

#define

G_CAPRAMATTR_3

0x0600

// Caption window #3 attr RAM base.

#define

G_CAPRAMATTR_4

0x0640

// Caption window #4 attr RAM base.

#define

G_CAPRAMATTR_5

0x0A00

// Caption window #5 attr RAM base.

#define

G_CAPRAMATTR_6

0x0A40

// Caption window #6 attr RAM base.

#define

G_CAPRAMATTR_7

0x0E00

// Caption window #7 attr RAM base.

#define

G_CAPRAMATTR_8

0x0E40

// Caption window #8 attr RAM base.

To load the attribute+selection data into the FPGA RAM blocks, use the following
method for the window/field data loading:

charbmpRAMbase = G_CAPRAMCHAR_#;
fpga_reg_write ( b, G_CAPRAMINDEX, charbmpRAMbase);

// set RAM start

for

( i=0; i

fpga_reg_write ( b, G_CAPRAMDATA, char_bmp_blk_#[i] );

}

Where, # could be 1, 2, 3, 4, 5, 6, 7, or 8 (window/field number); N is the total
number of the char or bitmap blocks in one window/field.