FT800 Series Programmer Guide
Version 2.1
Document Reference No.: BRT_000030 Clearance No.: BRT#037
140
Copyright © Bridgetek Limited
4.41
TAG
Attach the tag value for the following graphics objects drawn on the screen. The initial
tag buffer value is 255.
Encoding
31 24 23 8 7 0
0x03
Reserved
s
Parameters
s
Tag value. Valid value range is from 1 to 255.
Description
The initial value of the tag buffer of the FT800 is specified by command CLEAR_TAG
and taken effect by command CLEAR. TAG command can specify the value of the tag
buffer of the FT800 that applies to the graphics objects when they are drawn on the
screen. This TAG value will be assigned to all the following objects, unless the
TAG_MASK command is used to disable it. Once the following graphics objects are
drawn, they are attached with the tag value successfully. When the graphics objects
attached with the tag value are touched, the register REG_TOUCH_TAG will be updated
with the tag value of the graphics object being touched.
If there is no TAG commands in one display list, all the graphics objects rendered by
the display list will report tag value as 255 in REG_TOUCH_TAG when they were
touched.
Graphics context
The value of s is part of the graphics context, as described in section 4.1
See also
CLEAR_TAG, TAG_MASK
