Specifications

II-34 EPSON S1C62N82 TECHNICAL SOFTWARE

CHAPTER 3: PERIPHERAL CIRCUITS (LCD Driver)

• Displaying 7-segment (for 4 commons)

The LCD display routine using the assignment of Figure

3.6.3 can be programmed as follows.

Label Mnemonic/operand Comment

ORG 000H

RETD 3FH ;0 is displayed

RETD 06H ;1 is displayed

RETD 5BH ;2 is displayed

RETD 4FH ;3 is displayed

RETD 66H ;4 is displayed

RETD 6DH ;5 is displayed

RETD 7DH ;6 is displayed

RETD 27H ;7 is displayed

RETD 7FH ;8 is displayed

RETD 6FH ;9 is displayed

SEVENS: LD B,0 ;Set the address of jump

LD X,090H ;Set address of display memory

JPBA

When the above routine is called (by the CALL or CALZ

instruction) with any number from "0" to "9" set in the A

are displayed according to the contents of the A register.

Examples of

LCD driver control

program

DisplayA resister

Fig. 3.6.4

Data set in A register and

displayed patterns

The RETD instruction can be used to write data to the

display memory only if it is addressed using the X register.

(Addressing using the Y register is invalid.)

Note that the stack pointer must be set to a proper value

before the CALL (CALZ) instruction is executed.