AT90LS2333-4AI Atmel, AT90LS2333-4AI Datasheet - Page 40

• Manufacturer Part Number: AT90LS2333-4AI
• Description: IC MCU 2K 4MHZ A/D LV IT 32TQFP
• Manufacturer: Atmel
• Series: AVR® 90LSr

Specifications of AT90LS2333-4AI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 20
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 6 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TQFP, 32-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Serial Peripheral Interface - SPI
The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the AT90S2333/4433 and
peripheral devices or between several AVR devices. The AT90S2333/4433 SPI features include the following:
• Full-Duplex, 3-Wire Synchronous Data Transfer
• Master or Slave Operation
• LSB First or MSB First Data Transfer
• Four Programmable Bit Rates
• End of Transmission Interrupt Flag
• Write Collision Flag Protection
• Wake-up from Idle Mode
Figure 36. SPI Block Diagram
The interconnection between master and slave CPUs with SPI is shown in Figure 37. The PB5(SCK) pin is the clock output
in the master mode and is the clock input in the slave mode. Writing to the SPI data register of the master CPU starts the
SPI clock generator, and the data written shifts out of the PB3(MOSI) pin and into the PB3(MOSI) pin of the slave CPU.
After shifting one byte, the SPI clock generator stops, setting the end of transmission flag (SPIF). If the SPI interrupt enable
bit (SPIE) in the SPCR register is set, an interrupt is requested. The Slave Select input, PB2(SS), is set low to select an
individual slave SPI device. The two shift registers in the Master and the Slave can be considered as one distributed 16-bit
circular shift register. This is shown in Figure 37. When data is shifted from the master to the slave, data is also shifted in
the opposite direction, simultaneously. This means that during one shift cycle, data in the master and the slave are
interchanged.
AT90S/LS2333 and AT90S/LS4433
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