ATmega168 Automotive Atmel Corporation, ATmega168 Automotive Datasheet - Page 163

• Manufacturer Part Number: ATmega168 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega168 Automotive

• Flash (kbytes): 16 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 24
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 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: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 150
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

16.1.4
16.1.5
16.2
7530I–AVR–02/10
Data Modes
SPI Status Register – SPSR
SPI Data Register – SPDR
• Bit 7 – SPIF: SPI Interrupt Flag
When a serial transfer is complete, the SPIF Flag is set. An interrupt is generated if SPIE in
SPCR is set and global interrupts are enabled. If SS is an input and is driven low when the SPI is
in Master mode, this will also set the SPIF Flag. SPIF is cleared by hardware when executing the
corresponding interrupt handling vector. Alternatively, the SPIF bit is cleared by first reading the
SPI Status Register with SPIF set, then accessing the SPI Data Register (SPDR).
• Bit 6 – WCOL: Write COLlision Flag
The WCOL bit is set if the SPI Data Register (SPDR) is written during a data transfer. The
WCOL bit (and the SPIF bit) are cleared by first reading the SPI Status Register with WCOL set,
and then accessing the SPI Data Register.
• Bit 5..1 – Res: Reserved Bits
These bits are reserved bits in the ATmega48/88/168 and will always read as zero.
• Bit 0 – SPI2X: Double SPI Speed Bit
When this bit is written logic one the SPI speed (SCK Frequency) will be doubled when the SPI
is in Master mode (see
clock periods. When the SPI is configured as Slave, the SPI is only guaranteed to work at f
or lower.
The SPI interface on the ATmega48/88/168 is also used for program memory and EEPROM
downloading or uploading. See
The SPI Data Register is a read/write register used for data transfer between the Register File
and the SPI Shift Register. Writing to the register initiates data transmission. Reading the regis-
ter causes the Shift Register Receive buffer to be read.
There are four combinations of SCK phase and polarity with respect to serial data, which are
determined by control bits CPHA and CPOL. The SPI data transfer formats are shown in
16-3
nal, ensuring sufficient time for data signals to stabilize. This is clearly seen by summarizing
Table 16-2
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
and
Figure
and
Table
MSB
SPIF
R/W
16-4. Data bits are shifted out and latched in on opposite edges of the SCK sig-
R
X
7
0
7
16-3, as done below.
Table
WCOL
R/W
6
X
R
6
0
16-4). This means that the minimum SCK period will be two CPU
page 293
R/W
5
X
R
5
–
0
ATmega48/88/168 Automotive
for serial programming and verification.
R/W
4
X
R
4
–
0
R/W
3
X
R
3
–
0
R/W
X
2
R
2
–
0
R/W
X
1
R
1
–
0
SPI2X
LSB
R/W
R/W
X
0
0
0
Undefined
SPDR
SPSR
Figure
osc
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