Генериране на синусоида на STM32F3 с DMA - изкривен изход

Опитвам се да генерирам вълнова форма, използвайки const таблица, DMA и DAC.

Това е STM32F303VCT на платка Discovery F3.

Използвам libopencm3, но се надявам, че ще видите ясно какво се случва - всичко това са само функции за настройка на контролните регистри.

#define SINE_TABLE_LEN 256

static const uint16_t sine_table[] = {
    2047, 2097, 2147, 2198, 2248, 2298, 2347, 2397, 2446, 2496, 2544, 2593, 2641, 2689, 2737, 2784, 2830, 2877, 2922, 2967, 3012, 3056, 3099, 3142, 3184, 3226, 3266, 3306, 3346, 3384, 3422, 3458, 3494, 3530, 3564, 3597, 3629, 3661, 3691, 3721, 3749, 3776, 3803, 3828, 3852, 3875, 3897, 3918, 3938, 3957, 3974, 3991, 4006, 4020, 4033, 4044, 4055, 4064, 4072, 4079, 4084, 4088, 4092, 4093, 4094, 4093, 4092, 4088, 4084, 4079, 4072, 4064, 4055, 4044, 4033, 4020, 4006, 3991, 3974, 3957, 3938, 3918, 3897, 3875, 3852, 3828, 3803, 3776, 3749, 3721, 3691, 3661, 3629, 3597, 3564, 3530, 3494, 3458, 3422, 3384, 3346, 3306, 3266, 3226, 3184, 3142, 3099, 3056, 3012, 2967, 2922, 2877, 2830, 2784, 2737, 2689, 2641, 2593, 2544, 2496, 2446, 2397, 2347, 2298, 2248, 2198, 2147, 2097, 2047, 1997, 1947, 1896, 1846, 1796, 1747, 1697, 1648, 1598, 1550, 1501, 1453, 1405, 1357, 1310, 1264, 1217, 1172, 1127, 1082, 1038, 995, 952, 910, 868, 828, 788, 748, 710, 672, 636, 600, 564, 530, 497, 465, 433, 403, 373, 345, 318, 291, 266, 242, 219, 197, 176, 156, 137, 120, 103, 88, 74, 61, 50, 39, 30, 22, 15, 10, 6, 2, 1, 0, 1, 2, 6, 10, 15, 22, 30, 39, 50, 61, 74, 88, 103, 120, 137, 156, 176, 197, 219, 242, 266, 291, 318, 345, 373, 403, 433, 465, 497, 530, 564, 600, 636, 672, 710, 748, 788, 828, 868, 910, 952, 995, 1038, 1082, 1127, 1172, 1217, 1264, 1310, 1357, 1405, 1453, 1501, 1550, 1598, 1648, 1697, 1747, 1796, 1846, 1896, 1947, 1997
//  0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 240, 256, 272, 288, 304, 320, 336, 352, 368, 384, 400, 416, 432, 448, 464, 480, 496, 512, 528, 544, 560, 576, 592, 608, 624, 640, 656, 672, 688, 704, 720, 736, 752, 768, 784, 800, 816, 832, 848, 864, 880, 896, 912, 928, 944, 960, 976, 992, 1008, 1024, 1040, 1056, 1072, 1088, 1104, 1120, 1136, 1152, 1168, 1184, 1200, 1216, 1232, 1248, 1264, 1280, 1296, 1312, 1328, 1344, 1360, 1376, 1392, 1408, 1424, 1440, 1456, 1472, 1488, 1504, 1520, 1536, 1552, 1568, 1584, 1600, 1616, 1632, 1648, 1664, 1680, 1696, 1712, 1728, 1744, 1760, 1776, 1792, 1808, 1824, 1840, 1856, 1872, 1888, 1904, 1920, 1936, 1952, 1968, 1984, 2000, 2016, 2032, 2048, 2063, 2079, 2095, 2111, 2127, 2143, 2159, 2175, 2191, 2207, 2223, 2239, 2255, 2271, 2287, 2303, 2319, 2335, 2351, 2367, 2383, 2399, 2415, 2431, 2447, 2463, 2479, 2495, 2511, 2527, 2543, 2559, 2575, 2591, 2607, 2623, 2639, 2655, 2671, 2687, 2703, 2719, 2735, 2751, 2767, 2783, 2799, 2815, 2831, 2847, 2863, 2879, 2895, 2911, 2927, 2943, 2959, 2975, 2991, 3007, 3023, 3039, 3055, 3071, 3087, 3103, 3119, 3135, 3151, 3167, 3183, 3199, 3215, 3231, 3247, 3263, 3279, 3295, 3311, 3327, 3343, 3359, 3375, 3391, 3407, 3423, 3439, 3455, 3471, 3487, 3503, 3519, 3535, 3551, 3567, 3583, 3599, 3615, 3631, 3647, 3663, 3679, 3695, 3711, 3727, 3743, 3759, 3775, 3791, 3807, 3823, 3839, 3855, 3871, 3887, 3903, 3919, 3935, 3951, 3967, 3983, 3999, 4015, 4031, 4047, 4063, 4079
};    

void send_dac_sine()
{
    const uint32_t dma = DMA2;
    const uint32_t ch = DMA_CHANNEL3;

    dac_dma_disable(CHANNEL_1);
    dma_disable_channel(dma, ch);
    dma_channel_reset(dma, ch);

    // DMA config
    dma_enable_circular_mode(dma, ch);

    dma_set_peripheral_address(dma, ch, (uint32_t) &DAC_DHR12R1);
    dma_set_memory_address(dma, ch, (uint32_t) sine_table);

    dma_set_memory_size(dma, ch, DMA_CCR_MSIZE_16BIT); // uint16_t
    dma_set_peripheral_size(dma, ch, DMA_CCR_MSIZE_32BIT); // 32-bit register
    dma_set_number_of_data(dma, ch, SINE_TABLE_LEN);
    dma_enable_memory_increment_mode(dma, ch); // incr mem. addr
    dma_disable_peripheral_increment_mode(dma, ch); // keep periph addr
    dma_set_read_from_memory(dma, ch); // memory -> periph

    dma_set_priority(dma, ch, DMA_CCR_PL_VERY_HIGH);

    // launch

    dac_dma_enable(CHANNEL_1); // enable the DAC to send DMA requests
    dma_enable_channel(dma, ch);
}

DAC се задейства от TIMER6 TRGO.

Мисля, че трябва да има някакъв бъг в дефиницията на таблицата или адреса на паметта на таблицата.

DMA работи, виждам нещо изпратено до DAC.

Това обаче не е моята таблица - ето я начертана, както е уловена от ADC:

Какво може да не е наред?

пс. ако го оставя да работи по-дълго, получавам нещо това (периодично е)