Industrial Electronic Engineers, Inc.
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05464
S03875–21–0214
Van Nuys, California
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SHEET 15
3.6
Down–Loadable Special Characters
An added feature of the serial input module is the inclusion of a group of 206 special characters stored in its
memory. These supplement the character library of the LCD module and may be easily down loaded (up to
eight at a time) into the CG RAM of the display module for use in one display frame of the display. Thus, in
addition to being able to input his own character designs as described in section 4.4, the user has these
additional preformatted characters available. Note that all down loaded character data is lost and must be
reloaded after power has been removed.
To facilitate the use of these characters, a "subsequent data" instruction (17h) is used to inform the
microprocessor that the following two bytes of data identify (1) the location of the special character to be down
loaded, and (2) the CG RAM location where it is to be loaded. This instruction sequence is as follows.
17h
(1)
Character
Locations
00h – E5h
(2)
CG RAM
Locations
00h – 07h
Figure 10 defines the format of these special characters and their memory location used to select them. The
eight CG RAM locations to which they may be sent are from 00h to 07h.
