Function Set; Set Cg Ram Address; Set Dd Ram Address; Read Busy Flag And Address - Xilinx Spartan-3A User Manual

R
Table 5-3: Shift Patterns According to S/C and R/L Bits
(S/C)

Function Set

Sets the interface data length, the number of display lines, and the character font.
The Starter Kit board supports a single function set with value 0x28.
Execution Time: 40 μs

Set CG RAM Address

Sets 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

Sets the initial DD RAM address.
After this command, all subsequent read or write operations to the display are to or from
DD RAM. The addresses for displayed characters appear in
Execution Time: 40 μs

Read Busy Flag and Address

Reads the Busy flag (BF) to determine if an internal operation is in progress, and reads 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 the address counter. The address counter
is used for both CG RAM and DD RAM addresses. The specific context depends on the
most recent
Execution Time: 1 μs

Write Data to CG RAM or DD RAM

Writes data into DD RAM if the command follows a previous
command, or writes data into CG RAM if the command follows a previous
Address
Spartan-3A/3AN Starter Kit Board User Guide
UG334 (v1.0) May 28, 2007
DB3 DB2
(R/L)
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.
Shift the entire display to the left. The cursor follows the display shift. The
1 0
address counter is unchanged.
Shift the entire display to the right. The cursor follows the display shift. The
1 1
address counter is unchanged.
Set CG RAM Address
command.
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Operation
or Set DD RAM Address
LCD Controller
Figure 5-3.
command issued.
Set DD RAM Address
Set CG RAM
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