Specifications

9–8 EPSON
SED1278
Set CGRAM Address
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
01 ACR 40H to 7FH
RS = 0
This instruction
1. loads a new 6-bit address into the address counter.
2. sets the address counter to address CGRAM.
Once “Set CGRAM Address” has been executed, the
contents of the address counter will be automatically
modified after every access of CGRAM, as determined
by the “Entry Mode Set” instruction.
If the “Set CGRAM Address” instruction is issued by the
system MPU while the display is enabled, and if either
the cursor is on or blink is on, pseudo-cursor or pseudo-
blink appears. To prevent this, turn both the cursor and
display blink off before loading a new CGRAM address.
The active width of the address counter, when it is
addressing CGRAM, is 6-bits so the counter will wrap
around to 00H from 3FH if more than 64 bytes of data are
written to CGRAM.
Set DDRAM Address
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
1ADD
RS = 0 80H to CFH … 1 line
80H to A7H line 1 … 2 line
C0H to E7H line 2 … 2 line
This instruction
1. loads a new 7-bit address into the address counter.
2. sets the address counter to point to the DDRAM.
Once the “Set DDRAM Address” instruction has been
executed, the contents of the address counter will be
automatically modified after each access of DDRAM, as
selected by the “Entry Mode Set” instruction.
The SED1278 has only 80 DDRAM locations. The valid
address spaces for various display configurations are
listed in table 3.
TABLE 3 Valid CGRAM Address Ranges
Write Data
DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
DATA
RS = 1
This instruction writes the data in DB7 to DB0 into either
the CGRAM or the DDRAM. The RAM space (CG or
DD), and the address in that space, that is accessed
depends on whether a “Set CGRAM Address” or a “Set
DDRAM Address” instruction was last executed, and on
the parameters of that instruction.
The contents of the address counter will be automatically
modified after each “Write Data”, as determined by
“Entry Mode Set”. When data is written to the CGRAM,
the DB7, DB6 and DB5 bits are not displayed directly as
characters.
TABLE 2 Combinations of Display Lines and Duty Cycle
NF
Number of Duty Common Output Non-Selected Common
Line Ratio Signal Output Signal
0 0 1 line 1/8 COM1 to COM8 COM9 to COM16
0 1 1 line 1/11 COM1 to COM11 COM12 to COM16
1 * 2 lines 1/16 COM1 to COM16 —
Number of Lines Characters ADR
1-line 80 00H to 4FH
2-line
1st line 40 00H to 27H
2nd line 40 40H to 67H