Digilent 410-087P-KIT - Manual (Page 49)

Spartan-3E Starter Kit Board User Guide www.xilinx.com 49
UG230 (v1.0) March 9, 2006
LCD Controller R
Function Set
Sets interface data length, number of display lines, and character font.
The Starter Kit board supports a single function set with value 0x28.
Execution Time: 40
μs
Set CG RAM Address
Set the initial CG RAM address.
After this command, all subsequent read or write operations to the display are to or from
CG RAM.
Execution Time: 40 μs
Set DD RAM Address
Set the initial DD RAM address.
After this command, all subsequentsubsequent read or write operations to the display are
to or from DD RAM. The addresses for displayed characters appear in
Figure 5-3 .
Execution Time: 40 μs
Read Busy Flag and Address
Read the Busy flag (BF) to determine if an internal operation is in progress, and read the
current address counter contents.
BF = 1 indicates that an internal operation is in progress. The next instruction is not
accepted until BF is cleared or until the current instruction is allowed the maximum time to
execute.
This command also returns the present value of address counter. The address counter is
used for both CG RAM and DD RAM addresses. The specific context depends on the most
recent
Set CG RAM Address or Set DD RAM Address command issued.
Execution Time: 1
μs
Write Data to CG RAM or DD RAM
Write data into DD RAM if the command follows a previous Set DD RAM Address
command, or write data into CG RAM if the command follows a previous Set CG RAM
Address command.
Table 5-4: Shift Patterns According to S/C and R/L Bits
DB3
(S/C)
DB2
(R/L)
Operation
0 0 Shift the cursor position to the left. The address counter is decremented by one.
0 1 Shift the cursor position to the right. The address counter is incremented by one.
1 0
Shift the entire display to the left. The cursor follows the display shift. The
address counter is unchanged.
1 1
Shift the entire display to the right. The cursor follows the display shift. The
address counter is unchanged.