code for led matrix display

Using Arduino Programming Questions
#1

this is part of arduino code for a 48*8 LED matrix display…i didnt undrstand the terms SPCR,SPDR,SPSR ,MSTR ,<<. . . anyone please explain the logic of this code…thanks

void setupSPI() {
byte clr;
SPCR |= ( (1 << SPE) | (1 << MSTR) ); // enable SPI as master
//SPCR |= ( (1<<SPR1) | (1<<SPR0) ); // set prescaler bits
SPCR &= ~( (1 << SPR1) | (1 << SPR0) ); // clear prescaler bits
clr = SPSR; // clear SPI status reg
clr = SPDR; // clear SPI data reg
SPSR |= (1 << SPI2X); // set prescaler bits
//SPSR &= ~(1<<SPI2X); // clear prescaler bits

delay(10);
}

MSG_txt_1-16-16_48x8_v15.10.ino (12.5 KB)

#2

Find the datasheet for your processor on the Atmel website and all will be explained.

Look for the register descriptions for the SPI Control Register, the SPI Status Register and the SPI Data Register

#3

what about “<<”…is it an operator …??

#4

Yes, it is the left-shift operator.

#5