int main() init_uart_buffer(); unsigned char ch; while (1) if (c30_cbuf_get(&uart_rx, &ch) == 0) // process byte
// ------------------------------------------------------------ // 4. DSP FIXED-POINT UTILITY (C30 lacks saturating arithmetic) // ------------------------------------------------------------ #define Q15(x) ((int)((x) * 32768.0)) #define SATURATE_Q15(x) ( (x) > 32767 ? 32767 : ( (x) < -32768 ? -32768 : (x) ) ) mplab c30 compiler
This is a thoughtful request. The (for dsPIC30/33 and PIC24 families) is now legacy (superseded by XC16), but many engineers still maintain projects on it. int main() init_uart_buffer(); unsigned char ch; while (1)
cb->buffer[cb->head] = data; cb->head = next_head; return 0; -32768 : (x) ) ) This is a thoughtful request
// Example: MAC with saturation inline int mac_saturate(int acc, int a, int b) acc += a * b; if (acc > 32767) acc = 32767; if (acc < -32768) acc = -32768; return acc;
// Interrupt-safe put (disables interrupts) inline int c30_cbuf_put(c30_cbuf_t *cb, unsigned char data) unsigned int next_head = (cb->head + 1) & cb->mask; if (next_head == cb->tail) return -1; // full