File content as of revision 1:ed1c6618f739:

// Talkie library
// Copyright 2011 Peter Knight
// This code is released under GPLv2 license.

#include "Talkie.h"

Timeout timeout;
PwmOut  speaker(D6);

#define FS 8000 // Speech engine sample rate

uint8_t synthPeriod;
uint16_t synthEnergy;
int16_t synthK1,synthK2;
int8_t synthK3,synthK4,synthK5,synthK6,synthK7,synthK8,synthK9,synthK10;

uint8_t tmsEnergy[0x10] = {0x00,0x02,0x03,0x04,0x05,0x07,0x0a,0x0f,0x14,0x20,0x29,0x39,0x51,0x72,0xa1,0xff};
uint8_t tmsPeriod[0x40] = {0x00,0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2A,0x2B,0x2D,0x2F,0x31,0x33,0x35,0x36,0x39,0x3B,0x3D,0x3F,0x42,0x45,0x47,0x49,0x4D,0x4F,0x51,0x55,0x57,0x5C,0x5F,0x63,0x66,0x6A,0x6E,0x73,0x77,0x7B,0x80,0x85,0x8A,0x8F,0x95,0x9A,0xA0};
int16_t tmsK1[0x20]     = {-32064, -31872, -31808, -31680, -31552, -31424, -31232, -30848, -30592, -30336, -30016, -29696, -29376, -28928, -28480, -27968, -26368, -24256, -21632, -18368, -14528, -10048, -5184, 0, 5184, 10048, 14528, 18368, 21632, 24256, 26368, 27968};
int16_t tmsK2[0x20]     = {-20992, -19328, -17536, -15552, -13440, -11200, -8768, -6272, -3712, -1088, 1536, 4160, 6720, 9216, 11584, 13824, 15936, 17856, 19648, 21248, 22656, 24000, 25152, 26176, 27072, 27840, 28544, 29120, 29632, 30080, 30464, 32384};
int8_t tmsK3[0x10]     = {-110, -97, -83, -70, -56, -43, -29, -16, -2, 11, 25, 38, 52, 65, 79, 92};
int8_t tmsK4[0x10]      = {-82, -68, -54, -40, -26, -12, 1, 15};
int8_t tmsK5[0x10]     = {-82, -70, -59, -47, -35, -24, -12, -1, 11, 23, 34, 46, 57, 69, 81, 92};
int8_t tmsK6[0x10]      = {-64, -53, -42, -31, -20, -9, 3, 14, 25, 36, 47, 58, 69, 80, 91, 102};
int8_t tmsK7[0x10]      = {-77, -65, -53, -41, -29, -17, -5, 7, 19, 31, 43, 55, 67, 79, 90, 102};
int8_t tmsK8[0x08]      = {-64, -40, -16, 7, 31, 55, 79, 102};
int8_t tmsK9[0x08]      = {-64, -44, -24, -4, 16, 37, 57, 77};
int8_t tmsK10[0x08]     = {-51, -33, -15, 4, 22, 32, 59, 77};

void TIMEOUT(void);

void Talkie::setPtr(uint8_t* addr)
{
    ptrAddr = addr;
    ptrBit = 0;
}

// The ROMs used with the TI speech were serial, not byte wide.
// Here's a handy routine to flip ROM data which is usually reversed.
uint8_t Talkie::rev(uint8_t a)
{
    // 76543210
    a = (a>>4) | (a<<4); // Swap in groups of 4
    // 32107654
    a = ((a & 0xcc)>>2) | ((a & 0x33)<<2); // Swap in groups of 2
    // 10325476
    a = ((a & 0xaa)>>1) | ((a & 0x55)<<1); // Swap bit pairs
    // 01234567
    return a;
}
uint8_t Talkie::getBits(uint8_t bits)
{
    uint8_t value;
    uint16_t data;
    data = rev((*ptrAddr))<<8;
    if (ptrBit+bits > 8) {
        data |= rev((*(ptrAddr+1)));
    }
    data <<= ptrBit;
    value = data >> (16-bits);
    ptrBit += bits;
    if (ptrBit >= 8) {
        ptrBit -= 8;
        ptrAddr++;
    }
    return value;
}
void Talkie::say(uint8_t* addr)
{
    uint8_t energy;

    if (!setup) {
        // Auto-setup.
        //
        // Enable the speech system whenever say() is called.

        // Timer 2 set up as a 62500Hz PWM.
        //
        // The PWM 'buzz' is well above human hearing range and is
        // very easy to filter out.
        //
        speaker.period_us(16);

        // Unfortunately we can't calculate the next sample every PWM cycle
        // as the routine is too slow. So use Timer 1 to trigger that.

        // Timer 1 set up as a 8000Hz sample interrupt
        timeout.attach_us(TIMEOUT, 125);

        setup = 1;
    }

    setPtr(addr);
    do {
        uint8_t repeat;

        // Read speech data, processing the variable size frames.

        energy = getBits(4);
        if (energy == 0) {
            // Energy = 0: rest frame
            synthEnergy = 0;
        } else if (energy == 0xf) {
            // Energy = 15: stop frame. Silence the synthesiser.
            synthEnergy = 0;
            synthK1 = 0;
            synthK2 = 0;
            synthK3 = 0;
            synthK4 = 0;
            synthK5 = 0;
            synthK6 = 0;
            synthK7 = 0;
            synthK8 = 0;
            synthK9 = 0;
            synthK10 = 0;
        } else {
            synthEnergy = tmsEnergy[energy];
            repeat = getBits(1);
            synthPeriod = tmsPeriod[getBits(6)];
            // A repeat frame uses the last coefficients
            if (!repeat) {
                // All frames use the first 4 coefficients
                synthK1 = tmsK1[getBits(5)];
                synthK2 = tmsK2[getBits(5)];
                synthK3 = tmsK3[getBits(4)];
                synthK4 = tmsK4[getBits(4)];
                if (synthPeriod) {
                    // Voiced frames use 6 extra coefficients.
                    synthK5 = tmsK5[getBits(4)];
                    synthK6 = tmsK6[getBits(4)];
                    synthK7 = tmsK7[getBits(4)];
                    synthK8 = tmsK8[getBits(3)];
                    synthK9 = tmsK9[getBits(3)];
                    synthK10 = tmsK10[getBits(3)];
                }
            }
        }
        thread_sleep_for(25);
    } while (energy != 0xf);
}

#define CHIRP_SIZE 41
int8_t chirp[CHIRP_SIZE]        = {0, 42, -44, 50, -78, 18, 37, 20, 2, -31, -59, 2, 95, 90, 5, 15, 38, -4, -91, -91, -42, -35, -36, -4, 37, 43, 34, 33, 15, -1, -8, -18, -19, -17, -9, -10, -6, 0, 3, 2, 1};
void TIMEOUT(void)
{
    static uint8_t nextPwm;
    static uint8_t periodCounter;
    static int16_t x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10;
    int16_t u0,u1,u2,u3,u4,u5,u6,u7,u8,u9,u10;

    speaker = float(nextPwm) * 0.392;
//    sei();
    if (synthPeriod) {
        // Voiced source
        if (periodCounter < synthPeriod) {
            periodCounter++;
        } else {
            periodCounter = 0;
        }
        if (periodCounter < CHIRP_SIZE) {
            u10 = ((chirp[periodCounter]) * (uint32_t) synthEnergy) >> 8;
        } else {
            u10 = 0;
        }
    } else {
        // Unvoiced source
        static uint16_t synthRand = 1;
        synthRand = (synthRand >> 1) ^ ((synthRand & 1) ? 0xB800 : 0);
        u10 = (synthRand & 1) ? synthEnergy : -synthEnergy;
    }
    // Lattice filter forward path
    u9 = u10 - (((int16_t)synthK10*x9) >> 7);
    u8 = u9 - (((int16_t)synthK9*x8) >> 7);
    u7 = u8 - (((int16_t)synthK8*x7) >> 7);
    u6 = u7 - (((int16_t)synthK7*x6) >> 7);
    u5 = u6 - (((int16_t)synthK6*x5) >> 7);
    u4 = u5 - (((int16_t)synthK5*x4) >> 7);
    u3 = u4 - (((int16_t)synthK4*x3) >> 7);
    u2 = u3 - (((int16_t)synthK3*x2) >> 7);
    u1 = u2 - (((int32_t)synthK2*x1) >> 15);
    u0 = u1 - (((int32_t)synthK1*x0) >> 15);

    // Output clamp
    if (u0 > 511) u0 = 511;
    if (u0 < -512) u0 = -512;

    // Lattice filter reverse path
    x9 = x8 + (((int16_t)synthK9*u8) >> 7);
    x8 = x7 + (((int16_t)synthK8*u7) >> 7);
    x7 = x6 + (((int16_t)synthK7*u6) >> 7);
    x6 = x5 + (((int16_t)synthK6*u5) >> 7);
    x5 = x4 + (((int16_t)synthK5*u4) >> 7);
    x4 = x3 + (((int16_t)synthK4*u3) >> 7);
    x3 = x2 + (((int16_t)synthK3*u2) >> 7);
    x2 = x1 + (((int32_t)synthK2*u1) >> 15);
    x1 = x0 + (((int32_t)synthK1*u0) >> 15);
    x0 = u0;

    nextPwm = (u0>>2)+0x80;
}