ATMEGA6490A-AU Atmel, ATMEGA6490A-AU Datasheet - Page 41

• Manufacturer Part Number: ATMEGA6490A-AU
• Description: IC MCU AVR 64K FLASH 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA6490A-AU

• 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: 69
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TFQFP
• Processor Series: ATmega
• Core: AVR
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 69
• Number Of Timers: 3
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 85 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9.4
9.5
9.6
8284A–AVR–10/10
Idle Mode
ADC Noise Reduction Mode
Power-down Mode
level as when BOD is globally disabled by fuses. If BOD is disabled in software, the BOD func-
tion is turned off immediately after entering the sleep mode. Upon wake-up from sleep, BOD is
automatically enabled again. This ensures safe operation in case the VCC level has dropped
during the sleep period.
When the BOD has been disabled, the wake-up time from sleep mode will be approximately 60
µs to ensure that the BOD is working correctly before the MCU continues executing code. BOD
disable is controlled by bit 6, BODS (BOD Sleep) in the control register MCUCR, see
MCU Control Register” on page
modes, while a zero in this bit keeps BOD active. Default setting keeps BOD active, i.e. BODS
set to zero.
Writing to the BODS bit is controlled by a timed sequence and an enable bit, see
MCU Control Register” on page
Note:
When the SM2:0 bits are written to 000, the SLEEP instruction makes the MCU enter Idle mode,
stopping the CPU but allowing LCD controller, the SPI, USART, Analog Comparator, ADC, USI,
Timer/Counters, Watchdog, and the interrupt system to continue operating. This sleep mode
basically halts clk
Idle mode enables the MCU to wake up from external triggered interrupts as well as internal
ones like the Timer Overflow and USART Transmit Complete interrupts. If wake-up from the
Analog Comparator interrupt is not required, the Analog Comparator can be powered down by
setting the ACD bit in the Analog Comparator Control and Status Register – ACSR. This will
reduce power consumption in Idle mode. If the ADC is enabled, a conversion starts automati-
cally when this mode is entered.
When the SM2:0 bits are written to 001, the SLEEP instruction makes the MCU enter ADC
Noise Reduction mode, stopping the CPU but allowing the ADC, the external interrupts, the USI
start condition detection, Timer/Counter2, LCD Controller, and the Watchdog to continue operat-
ing (if enabled). This sleep mode basically halts clk
other clocks to run.
This improves the noise environment for the ADC, enabling higher resolution measurements. If
the ADC is enabled, a conversion starts automatically when this mode is entered. Apart form the
ADC Conversion Complete interrupt, only an External Reset, a Watchdog Reset, a Brown-out
Reset, an LCD controller interrupt, USI start condition interrupt, a Timer/Counter2 interrupt, an
SPM/EEPROM ready interrupt, an external level interrupt on INT0 or a pin change interrupt can
wake up the MCU from ADC Noise Reduction mode.
When the SM2:0 bits are written to 010, the SLEEP instruction makes the MCU enter Power-
down mode. In this mode, the external Oscillator is stopped, while the external interrupts, the
USI start condition detection, and the Watchdog continue operating (if enabled). Only an Exter-
nal Reset, a Watchdog Reset, a Brown-out Reset, USI start condition interrupt, an external level
ATmega169A/169PA/329A/329PA/649A/649P/3290A/3290PA/6490A/6490P
1. BOD disable only available in picoPower devices ATmega169A/329PA/3290PA/649P/6490P.
CPU
and clk
FLASH
45.
45. Writing this bit to one turns off the BOD in relevant sleep
, while allowing the other clocks to run.
I/O
, clk
CPU
, and clk
FLASH
, while allowing the
”MCUCR –
”MCUCR –
41