PS081 datasheet(150/155 Pages) AMSCO

150 / 155 page

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8-5

PSØ81

8.3

Code snippet for external LCD driver

In chapter 4 the support of an external LCD driver is explained. The following code snippet shows

basically how to program the SPI access to the external LCD driver. A simple measurement example

will be available in the assembler software soon.

Configuration:

equal 0x480540

; Config Register 64 ß

equal 0xE00700 ; Config Register 65 ß

equal 0x000000

; Config Register 66 ß

Constant declarations:

CONST spi_chip_select 9

CONST spi_data_out

CONST spi_clock

CONST lcd_reg_low_read

CONST lcd_reg_mid_read 99

CONST spi_bus

Initialization of Holtek HT1621 (realized as subroutine):

init_holtek:

;set initial state

ramadr 65

or r, 0x000700

;set pins lcd_spi_out to 1

;set duty cycle and number of common segments (Holtek)

move y, 0x0004A1

jsub send_command ;LSB of y is MSB to Holtek!!!

;turn on display (Holtek)

move y, 0x000601

jsub send_command

;turn on bias generator (Holtek)

move y, 0x000401

jsub send_command

;select crystal oscillator (Holtek)

move y, 0x000141

jsub send_command

jsubret

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PS081 Datasheet(PDF) 150 Page - ams AG