Digilent 410-087P-KIT - Manual (Page 45)

Spartan-3E Starter Kit Board User Guide www.xilinx.com 45
UG230 (v1.0) March 9, 2006
LCD Controller R
The character ROM contains the ASCII English character set and Japanese kana characters.
The controller also provides for eight custom character bitmaps, stored in CG RAM . These
eight custom characters are displayed by storing character codes 0x00 through 0x07 in a
DD RAM location.
CG RAM
The Character Generator RAM (CG RAM) provides space to create eight custom character
bitmaps. Each custom character location consists of a 5-dot by 8-line bitmap, as shown in
Figure 5-5 .
The Set CG RAM Address command initializes the address counter before reading or
writing to CG RAM. Write CG RAM data using the Write Data to CG RAM or DD RAM
command, and read CG RAM using the Read Data from CG RAM or DD RAM command.
Figure 5-4: LCD Character Set
Lo
wer Data Nibb
le
Upper Data Nibble
DB7
DB6
DB5
DB4
DB
3
DB2 DB1 DB0
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