PT6314_10 Datasheet, PDF (24/42 Pages) Princeton Technology Corp – Dot Character VFD Controller/Driver IC

PT6314
6.2 “CURSOR HOME” INSTRUCTION
RS R/W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
CODE 0
0
0
0
0
0
0
0
1
X
The CURSOR HOME Instruction performs the following operations:
1. Clears the contents of the Address Counter (ACC) to 00H.
2. Sets the Address Counter to point to the Display Data RAM (DDRAM).
3. Sets the Display for Zero Character Shift (Returns to the original position).
4. If the cursor is displayed, this instruction moves the cursor to the left most character in the upper line display.
6.3 “ENTRY MODE” INSTRUCTION
RS R/W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
CODE 0
0
0
0
0
0
0
01
1/D
S
The “I/D” Bit provides a way to modify the contents of the address counter after every access to the DDRAM or CGRAM.
When I/D is set to “1” the Address Counter is incremented after the DDRAM or CGRAM has been accessed. When the
I/D is set to “0” the Address Counter is decremented after the DDRAM or CGRAM has been accessed.
The “S” Bit controls the display or cursor shift after each read or write operation to the DDRAM. If S is set to “1” the
“Display Shift” Instruction is enabled. If the S is set to “0” the “Cursor Shift” Instruction is enabled.
The direction in which the display is shifted is opposite to that of the cursor. For example, if S=”0” and I/D=”1” the cursor
will shift one character to the right after the MCU writes to the DDRAM. But, if the S=”1” and I/D=”1” the display will shift
one character to the left and the cursor will remain in the same position in the panel display. The cursor has already been
shifted in the direction selected by the I/D during the reading of the DDRAM irrespective of the value of “S”. Reading and
writing the CGRAM always shifts the cursor. Both lines are shifted at the same time.
The table below shows the various cursor and display shift movements by the “Entry Mode Set”.
I/D
S
After Writing DDRAM Data
After Reading DDRAM Data
0
0
Cursor moves one character to the left. Cursor moves one character to the left.
1
0
Cursor moves one character to the right. Cursor moves one character to the right.
0
1
Display shifts one character to the right
without any cursor movement.
Cursor moves one character to the left.
1
1
Display shifts one character to the left
without any cursor movement.
Cursor moves one character to the right.
During Reset,
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0
0
0
0
0
1
1
0
V1.5
24
October 2009