| 0,0 → 1,155 |
|---|
| #include <xc.h> |
| #include <plib.h> |
| #include "defines.h" |
| #include "SPI1.h" |
| |
| static SPI1_DATA *data_ptr; |
| static void (*callback_function)(void); |
| |
| void SPI1_Init(SPI1_DATA *data) { |
| data_ptr = data; |
| data_ptr->outBufferInd = 0; |
| data_ptr->outBufferLen = 0; |
| #ifndef SPI1_WRITE_ONLY |
| data_ptr->inBufferInd = 0; |
| data_ptr->inBufferLen = 0; |
| #endif |
| |
| INTDisableInterrupts(); |
| |
| // Note: FIFO enhanced buffer depth is 4/8/16 for 32/16/8 bit widths |
| |
| // Alternative Configuration: |
| // The third value is the SPI bitrate which is 1/2 the frequency of the |
| // desired clock frequency. Thus 40Mhz / (20Mhz / 2) = 4. |
| // Note: SPI_OPEN_TBE_NOT_FULL should only be used at >10Mhz speeds |
| // SpiChnOpen(SPI_CHANNEL1, SPI_OPEN_MSTEN | SPI_OPEN_ENHBUF | SPI_OPEN_TBE_NOT_FULL | SPI_OPEN_RBF_NOT_EMPTY, 4); |
| // INTSetVectorPriority(INT_SPI_1_VECTOR, INT_PRIORITY_LEVEL_6); |
| // INTSetVectorSubPriority(INT_SPI_1_VECTOR, INT_SUB_PRIORITY_LEVEL_1); |
| // INTClearFlag(INT_SPI1E); |
| // INTClearFlag(INT_SPI1TX); |
| // INTClearFlag(INT_SPI1RX); |
| |
| // FSCK = FPB / (2 * (SPIxBRG + 1)) |
| IEC0CLR = 0x03800000; // Disable all SPI interrupts |
| SPI1CON = 0; // Stops and resets the SPI1. |
| int tmp = SPI1BUF; // Clears the receive buffer |
| IFS0CLR = 0x03800000; // Clear any existing event |
| IPC5CLR = 0x1F000000; // Clear the priority |
| IPC5SET = 0x19000000; // Set IPL=6, Subpriority 1 |
| SPI1BRG = 0x1; // Use FPB/4 clock frequency |
| SPI1STATCLR = 0x40; // Clear the Overflow |
| #ifndef SPI1_WRITE_ONLY |
| IEC0SET = 0x01800000; // Enable RX and Error interrupts |
| #endif |
| // Enhanced buffer, SPI on, 8 bits transfer, SMP=1, Master mode |
| // SPIxTXIF set on buffer empty, SPIxRXIF set on buffer not empty |
| SPI1CON = 0x18225; |
| |
| INTEnableInterrupts(); |
| } |
| |
| #ifndef SPI1_WRITE_ONLY |
| int SPI1_Read_Buffer(unsigned char *array, unsigned int count) { |
| if (count > SPI1_BUFFER_SIZE) |
| return 0; |
| if (data_ptr->inBufferLen == 0) |
| return 0; |
| |
| // Save previous interrupt state |
| int prev = IEC0 & 0x03800000; |
| // Temporarily disable interrupts |
| IEC0CLR = 0x03800000; |
| int ret = data_ptr->inBufferLen; |
| int i; |
| for (i = 0; i < count; i++) { |
| array[i] = data_ptr->inBuffer[i]; |
| } |
| // Reset buffer pointers |
| data_ptr->inBufferInd = 0; |
| data_ptr->inBufferLen = 0; |
| // Restore saved interrupt state |
| IEC0SET = prev; |
| // Return the number of valid bytes in the buffer |
| return ret; |
| } |
| #endif |
| |
| int SPI1_Write(unsigned char *array, unsigned int count, void (*callback)(void)) { |
| callback_function = callback; |
| |
| if (count > SPI1_BUFFER_SIZE) |
| return 0; |
| if (data_ptr->outBufferLen != 0) |
| return 0; |
| |
| data_ptr->outBufferLen = count; |
| data_ptr->outBufferInd = count-1; |
| int i; |
| for (i = 0; i < count; i++) { |
| data_ptr->outBuffer[i] = array[i]; |
| } |
| IEC0SET = 0x02000000; // Enable TX interrupt |
| return 1; |
| } |
| |
| void __ISR(_SPI_1_VECTOR, ipl6) __SPI_1_Interrupt_Handler(void) { |
| #ifndef SPI1_WRITE_ONLY |
| // Process SPI1 error flag |
| if (IFS0bits.SPI1EIF) { |
| // Clear the receive overflow bit if it is set |
| if (SPI1STATbits.SPIROV) { |
| SPI1STATbits.SPIROV = 0; |
| } |
| IFS0CLR = 0x00800000; // Clear the error flag |
| } |
| |
| // Process SPI1 receive flag |
| if (IFS0bits.SPI1RXIF) { |
| int i; |
| // Read the data received from the last transfer |
| int rxBufferCount = SPI1STATbits.RXBUFELM; |
| if (data_ptr->inBufferLen + rxBufferCount < SPI1_BUFFER_SIZE) { |
| for (i = 0; i < rxBufferCount; i++) { |
| data_ptr->inBuffer[data_ptr->inBufferInd] = SPI1BUF; |
| data_ptr->inBufferInd++; |
| data_ptr->inBufferLen++; |
| } |
| } else { |
| // If buffer is full, discard data in enhanced buffer |
| for (i = 0; i < rxBufferCount; i++) { |
| int tmp = SPI1BUF; |
| } |
| } |
| IFS0CLR = 0x01000000; // Clear the RX flag |
| } |
| #endif |
| |
| // Process SPI1 transmit flag |
| if (IFS0bits.SPI1TXIF) { |
| int i; |
| // Disable the transmit interrupt if all data has been sent |
| if (data_ptr->outBufferLen == 0) { |
| IEC0CLR=0x02000000; |
| if (callback_function != NULL) |
| (*callback_function)(); |
| } else { |
| // Start transmitting the data in the buffer |
| int txBufferFree = 16 - SPI1STATbits.TXBUFELM; |
| if (data_ptr->outBufferLen > txBufferFree) { |
| for (i = 0; i < txBufferFree; i++) { |
| SPI1BUF = data_ptr->outBuffer[data_ptr->outBufferInd]; |
| data_ptr->outBufferInd--; |
| } |
| data_ptr->outBufferLen -= txBufferFree; |
| } else { |
| for (i = 0; i < data_ptr->outBufferLen; i++) { |
| SPI1BUF = data_ptr->outBuffer[data_ptr->outBufferInd]; |
| data_ptr->outBufferInd--; |
| } |
| data_ptr->outBufferLen = 0; |
| } |
| } |
| IFS0CLR = 0x02000000; // Clear the TX flag |
| } |
| } |