ATTINY20-SSU Atmel, ATTINY20-SSU Datasheet - Page 131

• Manufacturer Part Number: ATTINY20-SSU
• Description: MCU AVR 2KB FLASH 12MHZ 14SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY20-SSU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 12MHz
• Connectivity: I²C, SPI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 12
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Ram Size: 128 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: *
• Processor Series: ATtiny
• Core: AVR
• Data Bus Width: 8 bit
• Data Ram Size: 128 B
• Interface Type: SPI, TWI
• Maximum Clock Frequency: 12 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 2
• 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
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

8235B–AVR–04/11
Low periods: Longer than 2 CPU clock cycles.
High periods: Longer than 2 CPU clock cycles.
When the SPI is enabled, the data direction of the MOSI, MISO, SCK, and SS pins is overridden
according to
“Alternate Port Functions” on page
Table 16-1.
Note:
The following code examples show how to initialize the SPI as a Master and how to perform a
simple transmission. DDR_SPI in the examples must be replaced by the actual Data Direction
Register controlling the SPI pins. DD_MOSI, DD_MISO and DD_SCK must be replaced by the
actual data direction bits for these pins. E.g. if MOSI is placed on pin PB5, replace DD_MOSI
with DDB5 and DDR_SPI with DDRB.
Assembly Code Example
MOSI
MISO
SCK
SPI_MasterInit:
SPI_MasterTransmit:
Wait_Transmit:
Pin
SS
; Set MOSI and SCK output, all others input
ldi
out
; Enable SPI, Master, set clock rate fck/16
ldi
out
ret
; Start transmission of data (r16)
out
; Wait for transmission complete
in
sbrsr16, SPIF
rjmp Wait_Transmit
ret
See
direction of the user defined SPI pins.
“Alternate Functions of Port B” on page 55
Table 16-1 on page
r17,(1<<DD_MOSI)|(1<<DD_SCK)
DDR_SPI,r17
r17,(1<<SPE)|(1<<MSTR)|(1<<SPR0)
SPCR,r17
SPDR,r16
r16, SPSR
SPI Pin Overrides
Direction, Master SPI
User Defined
Input
User Defined
User Defined
131. For more details on automatic port overrides, refer to
49.
for a detailed description of how to define the
Direction, Slave SPI
Input
User Defined
Input
Input
ATtiny20
131