PIC18, MPLAB X IDE, XC8, SPI, at45dbxx data flash

PIC18, MPLAB X IDE, XC8, SPI, at45dbxx data flash

4MHz frequency 에서 spi clock으로 1MHz를 사용합니다.

- RC3 : CLK
- RC4 : SDI
- RC5 : SDO
- RA5 : CS

0. 참고 사항

• https://openlabpro.com/guide/spi-module-in-pic18f4550/
• https://www.waveshare.com/wiki/Open18F4520
  
• [  ] https://www.microchip.com/wwwproducts/en/PIC18F4520
• [ datasheet ] http://ww1.microchip.com/downloads/en/devicedoc/39631a.pdf

1. HW 연결

2. 소스 설명

full 소스는 아래 github를 통해 확인하세요.

void init_spi( unsigned char sync_mode, unsigned char bus_mode, unsigned char smp_phase) {     TRIS_SDI = 1;               // SDI input     TRIS_SDO = 0;               // SD0 output             SSPSTAT &= 0x3F;        // power on state          SSPCON1 = 0x00;         // power on state     SSPCON1 |= sync_mode;   // select serial mode                                        // 0000 = SPI Master mode, clock = FOSC/4         SSPSTAT |= smp_phase;   // select data input sample phase     switch( bus_mode )     {         case 0:     // SPI bus mode 0,0             SSPSTATbits.CKE = 1;    // data transmitted on rising edge             break;             case 2:     // SPI bus mode 1,0             SSPSTATbits.CKE = 1;    // data transmitted on falling edge             SSPCON1bits.CKP = 1;    // clock idle state high             break;         case 3:     // SPI bus mode 1,1             SSPCON1bits.CKP = 1;    // clock idle state high             break;         default:    // default SPI bus mode 0,1             break;    }          switch( sync_mode )     {         case 4:             // slave mode w /SS enable             TRIS_SCK = 1;   // define clock pin as input                 TRIS_CS  = 1;   // define /SS1 pin as input             break;         case 5:             // slave mode w/o /SS enable             TRIS_SCK = 1;   // define clock pin as input                 break;                 default:            // master mode, define clock pin as output             TRIS_SCK = 0;   // define clock pin as output                 break;     }     SSPCON1 |= 0x20;            // enable synchronous serial port,  0b00100000  Enable serial port and configures SCK, SDO, SDI }

3. 소스

• https://github.com/sglee0223/pic18/tree/master/spi_at45dbxx.X
  

4. 결과