ATMEGA406-1AAU Atmel, ATMEGA406-1AAU Datasheet - Page 29

• Manufacturer Part Number: ATMEGA406-1AAU
• Description: IC AVR MCU 40K 1MHZ 48LQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA406-1AAU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 1MHz
• Connectivity: I²C
• Peripherals: POR, WDT
• Number Of I /o: 18
• Program Memory Size: 40KB (20K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 25 V
• Data Converters: A/D 10x12b
• Oscillator Type: Internal
• Operating Temperature: -30°C ~ 85°C
• Package / Case: 48-LQFP
• Processor Series: ATMEGA48x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: 2-Wire
• Maximum Clock Frequency: 1 MHz
• Number Of Programmable I/os: 18
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 30 C
• Cpu Family: ATmega
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 1MHz
• Total Internal Ram Size: 2KB
• # I/os (max): 18
• Number Of Timers - General Purpose: 2
• Operating Supply Voltage (typ): 5/9/12/15/18/24V
• Operating Supply Voltage (max): 25V
• Operating Supply Voltage (min): 4V
• On-chip Adc: 10-chx12-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -30C to 85C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 48
• Package Type: LQFP
• Controller Family/series: AVR MEGA
• No. Of I/o's: 18
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 2KB
• Cpu Speed: 1MHz
• Rohs Compliant: Yes
• For Use With: 770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPI
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.11
7.11.1
7.11.2
2548E–AVR–07/06
Register Description
FOSCCAL – Fast RC Oscillator Calibration Register
CCSR – Clock Control and Status Register
• Bits 7:0 – FCAL7:0: Fast RC Oscillator Calibration Value
The Fast RC Oscillator Calibration Register is used to trim the Fast RC Oscillator to remove pro-
cess variations from the oscillator frequency. The factory-calibrated value is automatically
written to this register during chip reset, giving an oscillator frequency of 4.0 MHz at 25°C. The
application software can write this register to change the oscillator frequency. The oscillator can
be calibrated to any frequency in the range 3.7 - 4.0 MHz within ±1% accuracy. Calibration out-
side that range is not guaranteed.
Note that this oscillator is used to time EEPROM and Flash write accesses, and these write
times will be affected accordingly. If the EEPROM or Flash are written, do not calibrate to more
than 4.4 MHz. Otherwise, the EEPROM or Flash write may fail.
The FCAL7 bit determines the range of operation for the oscillator. Setting this bit to 0 gives the
lowest frequency range, setting this bit to 1 gives the highest frequency range. The two fre-
quency ranges are overlapping, in other words a setting of FOSCCAL = 0x7F gives a higher
frequency than FOSCCAL = 0x80.
The FCAL6:0 bits are used to tune the frequency within the selected range. A setting of 0x00
gives the lowest frequency in that range, and a setting of 0x7F gives the highest frequency in the
range. Incrementing FCAL6:0 by 1 will give a frequency increment of less than 2% in the fre-
quency range 3.7 - 4.0 MHz.
• Bits 7:2 - Res: Reserved Bits
These bits are reserved bits in the ATmega406 and will always read as zero.
• Bit 1 - XOE: 32 kHz Crystal Oscillator Enable
The XOE bit is used to enable the 32 kHz Crystal Oscillator before it is selected as clock source.
This allows the Oscillator clock to stabilize prior to use. The 32 kHz Crystal Oscillator requires
approximately two seconds to stabilize, this must be timed by the user software. If the software
tries to write a one to ACS and a zero to XOE at the same time, both XOE and ACS will be
cleared by the hardware. Thus, while the 32 kHz Crystal Oscillator is disabled it is not possible to
select it as a clock source .
Bit
(0x66)
Read/Write
Initial Value
Bit
(0xC0)
Read/Write
Initial Value
FCAL7
R/W
7
R
7
–
0
FCAL6
R/W
6
R
6
–
0
FCAL5
R/W
5
R
5
–
0
Device Specific Calibration Value
FCAL4
R/W
4
R
4
–
0
FCAL3
R/W
3
R
3
–
0
FCAL2
R/W
2
R
2
–
0
FCAL1
R/W
XOE
R/W
1
1
0
ATmega406
FCAL0
R/W
ACS
R/W
0
0
0
FOSCCAL
CCSR
29