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What is SPI interrupt?
The SPI interrupt, when enabled, will be triggered based on different selectable events such as transmit buffer empty or a fault (see table). There is a single global interrupt vector for each SPI device on the STM32F103 so when it is tripped, the code needs to looks an SPI register to determine the source.
How SPI interrupt works?
When the SPRIE bit is set to 1, an interrupt is generated when the SPI receiver full bit, SPRF, is set. The SPRF bit is set when a byte of data is transferred to the SPI receive data register. The clock polarity bit, CPOL, is a read/write bit that determines the logic state of the SPSCK pin between transmissions.
Does SPI use interrupts?
The interrupt is raised by the SPI module and it is used to notify the microcontroller that a byte (or more) was received and it is ready for processing.
What is the Control Register of a SPI?
SPCR – SPI Control Register Bit 7 6 5 0 0x2C (0x4C) SPIE SPE DORD SPR0 Read/Write R/W R/W R/W R/W Initial Value 0 0 0 0
How does the SPI Register work in ATmega328P?
This bit causes the SPI interrupt to be executed if SPIF bit in the SPSR Register is set and the if the Global Interrupt Enable bit in SREG is set. When the SPE bit is written to one, the SPI is enabled. This bit must be set to enable any SPI operations. When the DORD bit is written to one, the LSB of the data word is transmitted first.
When is the SPE bit written to one, the SPI is enabled?
When the SPE bit is written to one, the SPI is enabled. This bit must be set to enable any SPI operations. When the DORD bit is written to one, the LSB of the data word is transmitted first. When the DORD bit is written to zero, the MSB of the data word is transmitted first.
How does SPI transfer data in Master Mode?
(Assuming you are in Master mode) There are two ways of transferring data using SPI: 1.Polling: Here you write data in SPI’s data register (SPDR) and then poll on the flag for SPI Transmission complete (SPIF). 2.Interrupt based: In this case, when you enable Interrupt for SPI, you write data in SPDR.