Specifications

EPSON 9–7
SED1278
SED1278
Write Only Instructions
Clear Display
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0000000101H
RS = 0
This instruction
1. loads all locations in the display data (DD) RAM
with 20H.
2. clears the contents of the address counter to 0H.
3. sets the display for zero character shift.
4. sets the address counter to point to the DDRAM.
5. , if the cursor is displayed, moves the cursor to the
left most character in the display or, if a two line
display is used, moves the cursor to the leftmost
character in the top line (line 1).
6. sets the address counter to increment on each access
of DDRAM or CGRAM.
Cursor Home
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0 0 0 0 0 0 1 * 02H, 03H
RS = 0
This instruction
1. clears the contents of the address counter to 0H.
2. sets the address counter to point to the DDRAM.
3. sets the display for zero character shift.
4. , if the cursor is displayed, moves the cursor to the
left most character in the display or, if a two line
display is used, the left most character in the top line
(line 1).
Entry Mode Set
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
000001I/DS 04H to 07H
RS = 0
• The I/D bit selects the way in which the contents of the
address counter are modified after every access to
DDRAM or CGRAM.
• I/D = 1: The address counter is incremented.
• I/D = 0: The address counter is decremented.
• The S bit enables display shift, instead of cursor shift,
after each write or read to the DDRAM.
• S = 1: Display shift enabled.
• S = 0: Cursor shift enabled.
The direction in which the display is shifted is opposite
in sense to that of the cursor. For example if S = 0 and
I/D = 1 the cursor would shift one character to the right
after an MPU write to DDRAM. However if S = 1 and
I/D = 1, the display would shift one character to the left
and the cursor would maintain its position on the
panel.
The cursor will already be shifted in the direction
selected by I/D during reads of the DDRAM,
irrespective of the value of S. Similarly reading and
writing the CGRAM always shifts the cursor. Note
that if a two line display is used both lines will be
shifted simultaneously.
Display ON/OFF
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
00001DCB 08H to 0FH
RS = 0
This instruction controls various features of the display.
• The D bit turns the entire display on or off.
• D = 1: Display on
• D = 0: Display off
• The C bit turns the cursor on or off.
• C = 1: Cursor on
• C = 0: Cursor off
• The B bit enables blinking of the character the cursor
coincides with.
• B = 1: Blinking on
• B = 0: Blinking off
Blinking is achieved by alternating between a normal
and all dark display of a character. The blinking
period is set at 204800 f
OSC. For example if fOSC = 250
kHz the cursor will blink with a period of 0.8192
seconds, or about 1.2 Hz.
Cursor/Display Shift
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
0001S/CR/L* * 10H to 1FH
RS = 0
This instruction shifts the display and/or moves the
cursor, on character to the left or right, regardless of a
DDRAM ready/write.
• The S/C bit selects movement of the cursor or
movement of both the cursor and the display.
• S/C = 1: Shift both cursor and display
• S/C = 0: Shift cursor only
• The R/L bit selects leftward or rightward movement of
the display and/or cursor.
• R/L = 1: Shift one character right
• R/L = 0: Shift one character left
System Set
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
001IFNF* * 20H to 3FH
RS = 0
This instruction initializes the system, and must be the
first instruction executed after power-on.
• The IF bit selects between an 8-bit or a 4-bit MPU
interface.
• IF = 1: 8-bit MPU interface using DB7 to DB0.
• IF = 0: 4-bit MPU interface using DB7 to DB4.
• The N and F bits select the number of display lines and
the corresponding duty cycle, as listed in table 2.