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Dot Character VFD Controller/Driver IC
PT6314
“ENTRY MODE” INSTRUCTION
RS R/W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
I/D
CODE
0
0
0
0
0
0
0
1
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
0
1
S
0
0
After Writing DDRAM Data
Cursor moves one character to the left. Cursor moves one character to the left.
Cursor moves one character to the right. Cursor moves one character to the right.
After Reading DDRAM Data
Display shifts one character to the right
Cursor moves one character to the left.
without any cursor movement.
Display shifts one character to the left Cursor moves one character to the right.
without any cursor movement.
0
1
1
1
During Reset,
DB7
DB6
DB5
DB4
DB3
DB2
DB1
DB0
0
0
0
0
0
1
1
0
PT6314 V1.3
- 25 -
March, 2006
PTC [ PRINCETON TECHNOLOGY CORP ]
