ATTINY24-15SSZ Atmel, ATTINY24-15SSZ Datasheet - Page 148

• Manufacturer Part Number: ATTINY24-15SSZ
• Description: MCU AVR 2K FLASH 15MHZ 14-SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY24-15SSZ

• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Speed: 16MHz
• Number Of I /o: 12
• Eeprom Size: 128 x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Program Memory Size: 2KB (2K x 8)
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: USI
• Core Size: 8-Bit
• Cpu Family: ATtiny
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 16MHz
• Interface Type: SPI/UART
• Total Internal Ram Size: 128Byte
• # I/os (max): 12
• Number Of Timers - General Purpose: 2
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 125C
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 14
• Package Type: SOIC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

18.10 Register Description
18.10.1
148
Atmel ATtiny24/44/84 [Preliminary]
ADMUX – ADC Multiplexer Selection Register
To obtain best accuracy the coefficient k should be measured using two temperature calibra-
tions. Using offset calibration, set k = 1.0, where k = (1024*1.07mV/°C)/1.1V~1.0 [1/°C].
• Bit 7:6 – REFS1:REFS0: Reference Selection Bits
These bits select the voltage reference for the ADC, as shown in
these bits are changed during a conversion, the change will not go in effect until this
conversion is complete (ADIF in ADCSR is set).
Special care should be taken when changing differential channels. Once a differential channel
has been selected, the stage may take as much as 25 ADC clock cycles to stabilize to the new
value. Thus conversions should not be started within the first 13 clock cycles after selecting a
new differential channel. Alternatively, conversion results obtained within this period should be
discarded.
The same settling time should be observed for the first differential conversion after changing
ADC reference (by changing the REFS1:0 bits in the ADMUX register).
For channels where differential gain is used (i.e., the gain stage), using VCC or an optional
external AREF higher than (VCC - 1V) is not recommended, as this will affect ADC accuracy.
The internal voltage reference may not be connected to the AREF pin if an external voltage is
already being applied to it. The internal voltage reference is connected to the AREF pin when
REFS1:0 is set to the value "11".
Table 18-3.
• Bits 5:0 – MUX5:0: Analog Channel and Gain Selection Bits
The value of these bits selects which combination of analog inputs are connected to the ADC.
In the case of differential input, gain selection is also made with these bits. Selections on
18-4 on page 149
and the offset calibration selections are located. Selecting the single-ended channel ADC8
enables the temperature measurement. See
are changed during a conversion, the change will not go into effect until this conversion is
complete (ADIF in ADCSRA is set).
Bit
0x07 (0x27)
Read/Write
Initial Value
REFS1
0
0
1
1
Voltage Reference Selections for ADC
REFS1
REFS0
R/W
7
0
0
1
0
1
show values for single-ended channels and where the differential channels
REFS0
R/W
6
0
Voltage Reference Selection
V
External Voltage Reference at PA0 (AREF) pin, Internal Voltage Reference
turned off.
Internal 1.1V Voltage Reference.
Reserved.
CC
used as analog reference, disconnected from PA0 (AREF).
MUX5
R/W
5
0
MUX4
R/W
4
0
Table 18-4 on page 149
MUX3
R/W
3
0
MUX2
R/W
2
0
Table 18-3 on page
MUX1
R/W
1
0
ffor details. If these bits
MUX0
R/W
0
0
7701D–AVR–09/10
ADMUX
148. If
Table