#if CPU==3052 #include "3052.h" #endif #if CPU==3048 #include "3048.h" #endif unsigned char ft245_get_byte(void) { unsigned char b1; unsigned char b; // wait until RXF# goes low while (PADR & 0x20); b = PADR; PADR = b & ~0x04; // /RD='L' b1 = P7DR; PADR = b; // /RD='H' return b1; } void init_ft245(void) { volatile unsigned long i; volatile unsigned char b; // wait until FT245RL is ready while (PADR & 0x40); // read garbage initially in the FIFO for (i = 0; i < 0x1000; ++i) { while (!(PADR & 0x20)) { b = ft245_get_byte(); } } } void init_port_for_mode7(void) { P4DR = 0x00; // P4DDR = 0xff; // set P4 (D0-D7) output (nothing connected) P3DR = 0x00; // P3DDR = 0xff; // set P3 (D8-D15) output (nothing connected) P1DR = 0x00; // P1DDR = 0xff; // set P1 (A0-A7) output P2DR = 0x00; P2DDR = 0xff; // set P2 (D0-D7) output P6DR = 0x00; // P61 = LRCK = L P6DDR = 0x02; // set P61 output PADR = 0x34; // PA2=/RD, PA3=WR, PA4=/TXE, PA5=/RXF, PA6=/PWREN PADDR = 0x8f; // /* N = Phi / (8 * 2^(2n-1) * B) * 1000000 - 1 1+N = Phi / (8 * 2^(2n-1) * B) * 1000000 (1+N)/1000000 = Phi / (8 * 2^(2n-1) * B) (1+N)/1000000 * B = Phi / (8 * 2^(2n-1)) B = 1000000 * Phi / (8 * 2^(2n-1)) / (1+N) if n = 0, Phi = 25 then B = 25000000 / 4 / (1+N) = 6250000 / (1+N) */ // init SCI0 (clock sync mode) SMR0 = 0x80; BRR0 = 0x01; /* ~3MHz clock */ asm ("nop"); asm ("nop"); asm ("nop"); asm ("nop"); asm ("nop"); asm ("nop"); asm ("nop"); asm ("nop"); asm ("nop"); asm ("nop"); SCR0 = 0x20; } #define SET_LRCK_HIGH (P6DR |= 0x02) #define SET_LRCK_LOW (P6DR &= ~0x02) const unsigned char swap_bit_lut[256] = { 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0, 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8, 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4, 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc, 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2, 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa, 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6, 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe, 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1, 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9, 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5, 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd, 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3, 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb, 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7, 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff }; void get_wav_info(unsigned long* filesize, unsigned short* gra_value) { unsigned char buf[0x2c]; unsigned char temp; unsigned long gra, size; unsigned short timeout; int i; RESTART: for (;;) { for (i = 0; i < sizeof(buf); ++i) { timeout = 0; while (PADR & 0x20) // wait until RXF# goes low { if (--timeout == 0) goto RESTART; } temp = PADR; PADR = temp & ~0x04; // /RD='L' buf[i] = P7DR; PADR = temp; // /RD='H' } // check header if (buf[0x00]=='R' && buf[0x01]=='I' && buf[0x02]=='F' && buf[0x03]=='F' && buf[0x08]=='W' && buf[0x09]=='A' && buf[0x0A]=='V' && buf[0x0B]=='E' && buf[0x10]==0x10 && buf[0x11]==0x00 && buf[0x12]==0x00 && buf[0x13]==0x00 && buf[0x14]==0x01 && buf[0x15]==0x00 && buf[0x16]==0x02 && buf[0x17]==0x00 && buf[0x24]=='d' && buf[0x25]=='a' && buf[0x26]=='t' && buf[0x27]=='a') { /* assume supported wav data */ break; } } // get data size size = (unsigned long)buf[0x28] + ((unsigned long)buf[0x29] << 8) + ((unsigned long)buf[0x2a] << 16) + ((unsigned long)buf[0x2b] << 24); // calculate GRA value from sample rate gra = 25000000UL / ((unsigned long)buf[0x18] + (unsigned long)buf[0x19] * 256); // don't support > 48kHz if (gra < 520UL) gra = 520UL; // don't support < 8000Hz if (gra > 3125UL) gra = 3125UL; *filesize = size; *gra_value = (unsigned short)gra; } void output_dac_zero(void) { const unsigned char z = 0x00; SET_LRCK_HIGH; // wait for TDRE while(!(SSR0 & 0x80)); // set upper byte to TDR TDR0 = z; SSR0 = 0x00; // start transmit // wait for TDRE while(!(SSR0 & 0x80)); // write lower byte TDR0 = z; SSR0 = 0x00; // wait for TDE while(!(SSR0 & 0x04)); SET_LRCK_LOW; // write upper byte TDR0 = z; SSR0 = 0x00; // start transmit // wait for TDRE while(!(SSR0 & 0x80)); // write lower byte TDR0 = z; SSR0 = 0x00; } int main(void) { unsigned char Ll, Lh, Rl, Rh, temp; unsigned long size; unsigned short gra, timeout; init_port_for_mode7(); init_ft245(); /* configure timer (ITU0) 25000000/44100 = 566.893424036 ~= 567 25000000/48000 = 520.833333333 ~= 521 25000000/8000 = 3125 */ TCR0 = 0x20; // clear TCNT on GRA match // GRA0 = 566; // ~=44100Hz @25MHz // GRA0 = 520; // ~=48000Hz @25MHz // TSTR = 0x01; // start ITU0 RESTART: while (1) { TSTR = 0x00; // stop ITU0 TCNT0 = 0x0000; // clear counter output_dac_zero(); get_wav_info(&size, &gra); GRA0 = gra; // set GRA0 TSTR = 0x01; // start ITU0 while (size) { timeout = 0; while (PADR & 0x20) // wait until RXF# goes low { if (--timeout == 0) goto RESTART; } temp = PADR; PADR = temp & ~0x04; // /RD='L' Ll = swap_bit_lut[P7DR]; PADR = temp; // /RD='H' timeout = 0; while (PADR & 0x20) // wait until RXF# goes low { if (--timeout == 0) goto RESTART; } temp = PADR; PADR = temp & ~0x04; // /RD='L' Lh = swap_bit_lut[P7DR]; PADR = temp; // /RD='H' timeout = 0; while (PADR & 0x20) // wait until RXF# goes low { if (--timeout == 0) goto RESTART; } temp = PADR; PADR = temp & ~0x04; // /RD='L' Rl = swap_bit_lut[P7DR]; PADR = temp; // /RD='H' timeout = 0; while (PADR & 0x20) // wait until RXF# goes low { if (--timeout == 0) goto RESTART; } temp = PADR; PADR = temp & ~0x04; // /RD='L' Rh = swap_bit_lut[P7DR]; PADR = temp; // /RD='H' // wait for timer expiration while (!(TSR0 & 1)); TSR0 = 0; SET_LRCK_HIGH; // wait for TDRE while(!(SSR0 & 0x80)); // set upper byte to TDR TDR0 = Lh; SSR0 = 0x00; // start transmit // wait for TDRE while(!(SSR0 & 0x80)); // write lower byte TDR0 = Ll; SSR0 = 0x00; // wait for TDE while(!(SSR0 & 0x04)); SET_LRCK_LOW; // write upper byte TDR0 = Rh; SSR0 = 0x00; // start transmit // wait for TDRE while(!(SSR0 & 0x80)); // write lower byte TDR0 = Rl; SSR0 = 0x00; size -= 4; } } return 0; }