unsigned char cklf; SPICLK = 0; // Max SPI clock SPI_CTRL = 0x02; // Connect SPI controller to Radio // switch to 16MHz clock: RACSN = 0; SpiReadWrite(RRC | 0x09); cklf = SpiReadWrite(0) | 0x04; RACSN = 1; RACSN = 0; SpiReadWrite(WRC | 0x09); SpiReadWrite(cklf); RACSN = 1; can i know what is meaning of RACSN, why RRC need to OR with 0x09, cklf = SpiReadWrite(0) | 0x04, SpiReadWrite(WRC | 0x09)and SpiReadWrite(cklf);?
"can i know what is meaning ..." Why yes, as a matter of fact, you can! The datasheet will have the details.
void NrfInit(void) { #ifdef nRF9E5 unsigned char cklf; SPICLK = 0; // Max SPI clock SPI_CTRL = 0x02; // Connect SPI controller to Radio // switch to 16MHz clock: RACSN = 0; SpiReadWrite(RRC | 0x09); cklf = SpiReadWrite(0) | 0x04; RACSN = 1; RACSN = 0; SpiReadWrite(WRC | 0x09); SpiReadWrite(cklf); RACSN = 1; #endif } !!!more info on!!! 1. SpiReadWrite OR RRC with 0x09? 2. SpiReadWrite(0) OR with 0x04? 3. SpiReadWrite(WRC | 0x09)? 4. SpiReadWrite(cklf)? As these codes will switch to 16MHz!... in nordic semiconductor nRF9E5 sample "rangedemo" programs
You really do need to read the Datasheet for the device! Your questions refer to the operation of the particular chip - they have nothing specifically to do with Keil Software! The Datasheet will explain to you the functions of the various registers. This will show you what happens when you write certain values to certain registers. "sample 'rangedemo' programs" For information about such programs, you need to consult the author of the proram - and see the provided documentation.