Writing data to the display, Disabling the unused lcd, Related resources – Xilinx MIcroblaze Development Spartan-3E 1600E User Manual
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MicroBlaze Development Kit Spartan-3E 1600 Edition User Guide
UG257 (v1.1) December 5, 2007
Chapter 5:
Character LCD Screen
R
x
Finally, issue a
command. Allow at least 1.64 ms (82,000 clock cycles)
after issuing this command.
Writing Data to the Display
To write data to the display, specify the start address, followed by one or more data values.
Before writing any data, issue a
command to specify the initial 7-bit
address in the DD RAM. See
for DD RAM locations.
Write data to the display using a
Write Data to CG RAM or DD RAM
command. The 8-bit
data value represents the look-up address into the CG ROM or CG RAM, shown in
Figure 5-4
. The stored bitmap in the CG ROM or CG RAM drives the 5 x 8 dot matrix to
represent the associated character.
If the address counter is configured to auto-increment, as described earlier, the application
can sequentially write multiple character codes and each character is automatically stored
and displayed in the next available location.
Continuing to write characters, however, eventually falls off the end of the first display
line. The additional characters do not automatically appear on the second line because the
DD RAM map is not consecutive from the first line to the second.
Disabling the Unused LCD
If the FPGA application does not use the character LCD screen, drive the LCD_E pin Low
to disable it. Also drive the LCD_RW pin Low to prevent the LCD screen from presenting
data.
Related Resources
x
Initial Design for Spartan-3E MicroBlaze Development Kit (Reference Design)
x
PowerTip PC1602-D Character LCD (Basic Electrical and Mechanical Data)
x
Sitronix ST7066U Character LCD Controller
x
Detailed Data Sheet on PowerTip Character LCD
x
Samsung S6A0069X Character LCD Controller