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ATmega169V/L

2514A–AVR–08/02

LCD Control and Status

• Bit 7 – LCDCS: LCD Clock Select

When this bit is written to zero, the system clock is used. When this bit is written to one,

the external asynchronous clock source is used. The asynchronous clock source is

either Timer/Counter Oscillator or external clock, depending on EXCLK in ASSR. See

“Asynchronous operation of the Timer/Counter” on page 137 for futher details.

• Bit 6 – LCD2B: LCD 1/2 Bias Select

When this bit is written to zero, 1/3 bias is used. When this bit is written to one, ½ bias is

used. Refer to the LCD Manufacture for recommended bias selection.

• Bit 5:4 – LCDMUX1:0: LCD Mux Select

The LCDMUX1:0 bits determine the duty cycle. Common pins that are not used are ordi-

nary port pins. The different duty selections are shown in Table 94.

Note: 1. 1/2 bias when LCD2B is written to one and 1/3 otherwise.

• Bit 3 – Res: Reserved Bit

This bit is reserved bit in the ATmega169 and will always read as zero.

Bit 765 43210

LCDCS LCD2B LCDMUX1 LCDMUX0 – LCDPM2 LCDPM1 LCDPM0 LCDCRB

Read/Write R/W R/W R/W R/W R R/W R/W R/W

Initial Value 0 0 0 0 0 0 0 0

Table 94. LCD Duty Select

LCDMUX1 LCDMUX0 Duty Bias COM Pin I/O Port Pin

0 0 Static Static COM0 COM1:3

0 1 1/2 1/2 or 1/3

(1)

COM0:1 COM2:3

1 0 1/3 1/2 or 1/3

(1)

COM0:2 COM3

1 1 1/4 1/2 or 1/3

(1)

COM0:3 None

1 2 ... 215 216 217 218 219 220 221 222 223 224 225 ... 316 317

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Rainbow-electronics Atmega169L Bedienungsanleitung Seite 220