FT800 Series Programmer Guide
Version 2.1
Document Reference No.: BRT_000030 Clearance No.: BRT#037
245
Copyright © Bridgetek Limited
5.54
CMD_SNAPSHOT - take a snapshot of the current screen
This command causes the co-processor engine to take a snapshot of the current screen,
and write the result into RAM_G as a ARGB4 bitmap. The size of the bitmap is the size of
the screen, given by the REG_HSIZE and REG_VSIZE registers.
During the snapshot process, the display should be disabled by setting REG_PCLK to 0 to
avoid display glitch.
Because co-processor engine needs to write the result into the destination address, the
destination address must be never used or referenced by graphics engine.
C prototype
void cmd_snapshot( uint32_t ptr );
Parameters
ptr
Snapshot destination address, in RAM_G
Command layout
+0
CMD_SNAPSHOT(0xffffff1f)
+4
ptr
Examples
To take a snapshot of the current 160 x 120 screen, then use it as a bitmap in the
new display list:
wr
(
REG_PCLK
,
0
);
//Turn off the PCLK
wr16
(
REG_HSIZE
,
120
);
wr16
(
REG_WSIZE
,
160
);
cmd_snapshot
(
0
);
//Taking snapshot.
wr
(
REG_PCLK
,
5
);
//Turn on the PCLK
wr16
(
REG_HSIZE
,
272
);
wr16
(
REG_WSIZE
,
480
);
cmd_dlstart
();
cmd
(
CLEAR
(
1
,
1
,
1
));
cmd
(
BITMAP_SOURCE
(
0
));
cmd
(
BITMAP_LAYOUT
(
ARGB4
,
2
*
160
,
120
));
cmd
(
BITMAP_SIZE
(
NEAREST
,
BORDER
,
BORDER
,
160
,
120
));
cmd
(
BEGIN
(
BITMAPS
));
cmd
(
VERTEX2II
(
10
,
10
,
0
,
0
));
Code snippet 18 CMD_SNAPSHOT 160x120–screen
