Xilinx MIcroblaze Development Spartan-3E 1600E - Manual (Page 47)

MicroBlaze Development Kit Spartan-3E 1600 Edition User Guide 45
UG257 (v1.1) December 5, 2007 www.xilinx.com
LCD Controller R
binary and the lower nibble equates to DB[3:0] = “0011” binary. As shown in Figure 5-4 , the
character ‘S’ appears on the screen.
English/Roman characters are stored in CG ROM at their equivalent ASCII code address.
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
w
er D
at
a Ni
bb
le
Upper Data Nibble
DB7
DB6
DB5
DB4
DB
3
DB2 DB1 DB0
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