ATMEGA329P-20MN Atmel, ATMEGA329P-20MN Datasheet - Page 242

• Manufacturer Part Number: ATMEGA329P-20MN
• Description: IC MCU AVR 32K 20MHZ 64QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA329P-20MN

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-MLF®, 64-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

23.5.2
8021G–AVR–03/11
LCDCRB – LCD Control and Status Register B
• Bit 0 – LCDBL: LCD Blanking
When this bit is written to one, the display will be blanked after completion of a frame. All seg-
ment and common pins will be driven to ground.
Note:
• 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
Operation of Timer/Counter2” on page 152
• 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 ordinary port
pins. The different duty selections are shown in
Table 23-2.
Note:
• Bits 3:0 – LCDPM3:0: LCD Port Mask
The LCDPM3:0 bits determine the number of port pins to be used as segment drivers. The dif-
ferent selections are shown in
Table 23-3.
Bit
(0xE5)
Read/Write
Initial Value
LCDPM3
LCDMUX1
0
0
0
0
0
0
1
1
Bit 3, LCDPM3 is only available in ATmega3290P.
1. 1/2 bias when LCD2B is written to one and 1/3 otherwise.
LCDCS
R/W
LCDPM2
LCD Duty Select
LCD Port Mask (Values in bold are only available in ATmega3290P)
7
0
LCDMUX0
0
0
0
0
0
1
0
1
LCD2B
R/W
6
0
LCDPM1
0
0
1
1
LCDMUX1
Table
R/W
5
0
Static
Duty
1/2
1/3
1/4
23-3. Unused pins can be used as ordinary port pins.
LCDPM0
LCDMUX0
0
1
0
1
R/W
for further details.
4
0
1/2 or 1/3
1/2 or 1/3
1/2 or 1/3
Table
Static
Bias
LCDPM3
R/W
I/O Port in Use as
Segment Driver
3
0
(1)
(1)
(1)
23-2.
SEG0:12
SEG0:14
SEG0:16
SEG0:18
ATmega329P/3290P
LCDPM2
COM Pin
R/W
COM0:1
COM0:2
COM0:3
COM0
2
0
LCDPM1
R/W
1
0
Maximum Number
of Segments
LCDPM0
I/O Port Pin
R/W
”Asynchronous
COM1:3
COM2:3
0
0
COM3
None
13
15
17
19
LCDCRB
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