ATMEGA169 ATMEL [ATMEL Corporation], ATMEGA169 Datasheet - Page 217

• Manufacturer Part Number: ATMEGA169
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Updating the LCD
2514P–AVR–07/06
Note:
Before a re-initialization is done, the LCD controller/driver should be disabled
Display memory (LCDDR0, LCDDR1, ..), LCD Blanking (LCDBL), Low power waveform
(LCDAB) and contrast control (LCDCCR) are latched prior to every new frame. There
are no restrictions on writing these LCD Register locations, but an LCD data update may
be split between two frames if data are latched while an update is in progress. To avoid
this, an interrupt routine can be used to update Display memory, LCD Blanking, Low
power waveform, and contrast control, just after data are latched.
Assembly Code Example
C Code Example
LCD_Init:
Void LCD_Init(void);
{
}
; Use 32 kHz crystal oscillator
; 1/3 Bias and 1/3 duty, SEG21:SEG24 is used as port pins
ldi
sts
; Using 16 as prescaler selection and 7 as LCD Clock Divide
; gives a frame rate of 49 Hz
ldi
sts
; Set segment drive time to 125 µs and output voltage to 3.3 V
ldi
sts
; Enable LCD, default waveform and no interrupt enabled
ldi
sts
ret
/* Use 32 kHz crystal oscillator */
/* 1/3 Bias and 1/3 duty, SEG21:SEG24 is used as port pins */
LCDCRB = (1<<LCDCS) | (1<<LCDMUX1)| (1<<LCDPM2);
/* Using 16 as prescaler selection and 7 as LCD Clock Divide */
/* gives a frame rate of 49 Hz */
LCDFRR = (1<<LCDCD2) | (1<<LCDCD1);
/* Set segment drive time to 125 µs and output voltage to 3.3 V*/
LCDCCR = (1<<LCDDC1) | (1<<LCDCC3) | (1<<LCDCC2) | (1<<LCDCC1);
/* Enable LCD, default waveform and no interrupt enabled */
LCDCRA = (1<<LCDEN);
1. See “About Code Examples” on page 6.
r16, (1<<LCDCS) | (1<<LCDMUX1)| (1<<LCDPM2)
LCDCRB, r16
r16, (1<<LCDCD2) | (1<<LCDCD1)
LCDFRR, r16
r16, (1<<LCDDC1) | (1<<LCDCC3) | (1<<LCDCC2) | (1<<LCDCC1)
LCDCCR, r16
r16, (1<<LCDEN)
LCDCRA, r16
(1)
(1)
ATmega169/V
217