ATtiny48 Atmel Corporation, ATtiny48 Datasheet - Page 37

• Manufacturer Part Number: ATtiny48
• Manufacturer: Atmel Corporation

Specifications of ATtiny48

• Flash (kbytes): 4 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 12 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 28
• Ext Interrupts: 28
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.25
• Eeprom (bytes): 64
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 2
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

7.1.2
7.1.3
7.2
8008H–AVR–04/11
Software BOD Disable
ADC Noise Reduction Mode
Power-Down Mode
Idle mode enables the MCU to wake up from external triggered interrupts as well as internal
ones like the SPI 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 automatically when this mode is entered.
When the SM[1:0] bits are written to 01, the SLEEP instruction makes the MCU enter ADC
Noise Reduction mode, stopping the CPU but allowing the ADC, the external interrupts, the 2-
wire Serial Interface address watch and the Watchdog to continue operating (if enabled). This
sleep mode basically halts clk
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 from the
ADC Conversion Complete interrupt, only an External Reset, a Watchdog System Reset, a
Watchdog Interrupt, a Brown-out Reset, a 2-wire Serial Interface address match, an EEPROM
ready interrupt, an external level interrupt on INT0 or INT1 or a pin change interrupt can wake up
the MCU from ADC Noise Reduction mode.
When the SM[1:0] bits are written to 10, the SLEEP instruction makes the MCU enter Power-
down mode. In this mode, the external oscillator is stopped, while the external interrupts, the 2-
wire Serial Interface address watch, and the Watchdog continue operating (if enabled). Only an
External Reset, a Watchdog System Reset, a Watchdog Interrupt, a Brown-out Reset, a 2-wire
Serial Interface address match, an external level interrupt on INT0 or INT1, or a pin change
interrupt can wake up the MCU. This sleep mode basically halts all generated clocks, allowing
operation of asynchronous modules only.
Note that if a level triggered interrupt is used for wake-up from Power-down mode, the changed
level must be held for some time to wake up the MCU. Refer to
for details.
When waking up from Power-down mode, there is a delay from the wake-up condition occurs
until the wake-up becomes effective. This allows the clock to restart and become stable after
having been stopped. The wake-up period is defined by the same CKSEL Fuses that define the
Reset Time-out period, as described in
When the Brown-out Detector (BOD) is enabled by BODLEVEL fuses (see
189), the BOD is actively monitoring the power supply voltage during a sleep period. To save
power, it is possible for software to disable the BOD in Power-down mode. The sleep mode
power consumption will then be at the same level as when BOD is globally disabled by fuses. If
disabled by software, the BOD is turned off immediately after entering the sleep mode and auto-
matically turned on upon wake-up. This ensures safe operation in case the V
dropped during the sleep period.
When the BOD has been disabled the wake-up time from sleep mode will be the same as the
wake-up time from RESET. This is in order to ensure 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
“MCUCR – MCU Control Register” on page
I/O
, clk
CPU
, and clk
“Clock Sources” on page
40. Writing this bit to one turns off the BOD in
FLASH
, while allowing the other clocks to run.
“External Interrupts” on page 53
29.
ATtiny48/88
Table 20-4 on page
CC
level has
37