ATMEGA163L-4AC Atmel, ATMEGA163L-4AC Datasheet - Page 37

• Manufacturer Part Number: ATMEGA163L-4AC
• Description: IC AVR MCU 16K A/D 2.7V 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA163L-4AC

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Calibrated Internal RC
Oscillator
Oscillator Calibration Register
– OSCCAL
Special Function I/O Register
– SFIOR
1142E–AVR–02/03
The calibrated internal Oscillator provides a fixed 1 MHz (nominal) clock at 5V and
25 C. This clock may be used as the system clock. See the section “Clock Options” on
page 5 for information on how to select this clock as the system clock. This Oscillator
can be calibrated by writing the calibration byte to the OSCCAL Register. When this
Oscillator is used as the chip clock, the Watchdog Oscillator will still be used for the
Watchdog Timer and for the Reset Time-out. At 5V and 25
bration byte gives a frequency within ± 1% of the nominal frequency. For details on how
to use the pre-programmed calibration value, see “Calibration Byte” on page 144.
• Bits 7..0 – CAL7..0: Oscillator Calibration Value
Writing the calibration byte to this address will trim the internal Oscillator to remove pro-
cess variations from the Oscillator frequency. When OSCCAL is zero, the lowest
available frequency is chosen. Writing non-zero values to this register will increase the
frequency of the internal Oscillator. Writing $FF to the register gives the highest avail-
able frequency.
The calibrated Oscillator is used to time EEPROM and Flash access. If EEPROM or
Flash is written, do not calibrate to more than 10% above the nominal frequency. Other-
wise, the EEPROM or Flash write operation may fail. Note that the Oscillator is intended
for calibration to 1.0MHz, thus tuning to other values is not guaranteed.
Table 10. Internal RC Oscillator Frequency Range.
• Bit 7..4 – Res: Reserved Bits
These bits are reserved bits in the ATmega163 and always read as zero.
• Bit 3 – ACME: Analog Comparator Multiplexer Enable
When this bit is set (one) and the ADC is switched off (ADEN in ADCSR is zero), the
ADC multiplexer selects the negative input to the Analog Comparator. When this bit is
cleared (zero), AIN1 is applied to the negative input of the Analog Comparator. For a
detailed description of this bit, see “Analog Comparator Multiplexed Input” on page 104.
Bit
$31 ($51)
Read/Write
Initial Value
Bit
$30 ($50)
Read/Write
Initial Value
OSCCAL Value
$FF
$00
$7F
CAL7
R
7
–
0
R/W
7
0
CAL6
R/W
R
6
–
0
6
0
CAL5
R/W
5
0
R
5
–
0
Min Frequency (MHz)
CAL4
R/W
4
0
R
0.5
0.7
1.0
4
–
0
CAL3
R/W
ACME
3
0
R/W
3
0
CAL2
R/W
2
0
PUD
R/W
o
2
0
C, the pre-programmed cali-
ATmega163(L)
Max Frequency (MHz)
CAL1
R/W
PSR2
1
0
R/W
1
0
1.0
1.5
2.0
CAL0
PSR10
R/W
R/W
0
0
0
0
SFIOR
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