Specifications

S1C6S2N7 TECHNICAL SOFTWARE EPSON II-33
CHAPTER 3: PERIPHERAL CIRCUITS (LCD Driver)
• Bit-unit operation of the display memory
Label Mnemonic/operand Comment
LD X,SEGBUF ;Set address display
;memory buffer
LD Y,090H ;Set address display memory
LD MX,3 ;Set buffer data
LD MY,MX ;SEG-A, B ON (●●, ▲▲)
AND MX,1110B ;Change buffer data
LD MY,MX ;SEG-A OFF (●, ▲▲)
AND MX,1101B ;Change buffer data
LD MY,MX ;SEG-B OFF (●, ▲)
For manipulation of the display memory in bit-units for the
assignment of Figure 3.5.5, a buffer must be provided in
RAM to hold data. Note that, since the display memory is
write-only, data cannot be changed directly using an ALU
instruction (for example, AND or OR).
After manipulating the data in the buffer, write it into the
corresponding display memory using the transfer command.
Fig. 3.5.5
Example of segment
assignment
▲●
090H
D3 D2 D1 D0
Address
Data
▲
●
: SEG-A
: SEG-B