コード例 #1
0
ファイル: ps2.c プロジェクト: WonjoonLee/tmk_keyboard
// TODO: send using interrupt if available
uint8_t ps2_host_send(uint8_t data)
{
    uint8_t res = 0;
    bool parity = true;
    ps2_error = PS2_ERR_NONE;
#ifdef PS2_USE_INT
    PS2_INT_OFF();
#endif
    /* terminate a transmission if we have */
    inhibit();
    _delay_us(200); // at least 100us

    /* start bit [1] */
    data_lo();
    clock_hi();
    WAIT(clock_lo, 20000, 10);   // may take 15ms at most until device starts clocking
    /* data [2-9] */
    for (uint8_t i = 0; i < 8; i++) {
        _delay_us(15);
        if (data&(1<<i)) {
            parity = !parity;
            data_hi();
        } else {
            data_lo();
        }
        WAIT(clock_hi, 50, 2);
        WAIT(clock_lo, 50, 3);
    }
    /* parity [10] */
    _delay_us(15);
    if (parity) { data_hi(); } else { data_lo(); }
    WAIT(clock_hi, 50, 4);
    WAIT(clock_lo, 50, 5);
    /* stop bit [11] */
    _delay_us(15);
    data_hi();
    /* ack [12] */
    WAIT(data_lo, 50, 6);
    WAIT(clock_lo, 50, 7);

    /* wait for idle state */
    WAIT(clock_hi, 50, 8);
    WAIT(data_hi, 50, 9);

#ifdef PS2_USE_INT
    PS2_INT_ON();
#endif
    res = ps2_host_recv_response();
ERROR:
#ifdef PS2_USE_INT
    PS2_INT_ON();
    idle();
#else
    inhibit();
#endif
    return res;
}
コード例 #2
0
ファイル: ps2_interrupt.c プロジェクト: 0mark/tmk_keyboard
uint8_t ps2_host_send(uint8_t data)
{
    bool parity = true;
    ps2_error = PS2_ERR_NONE;

    PS2_INT_OFF();

    /* terminate a transmission if we have */
    inhibit();
    _delay_us(100); // 100us [4]p.13, [5]p.50

    /* 'Request to Send' and Start bit */
    data_lo();
    clock_hi();
    WAIT(clock_lo, 10000, 10);   // 10ms [5]p.50

    /* Data bit[2-9] */
    for (uint8_t i = 0; i < 8; i++) {
        _delay_us(15);
        if (data&(1<<i)) {
            parity = !parity;
            data_hi();
        } else {
            data_lo();
        }
        WAIT(clock_hi, 50, 2);
        WAIT(clock_lo, 50, 3);
    }

    /* Parity bit */
    _delay_us(15);
    if (parity) { data_hi(); } else { data_lo(); }
    WAIT(clock_hi, 50, 4);
    WAIT(clock_lo, 50, 5);

    /* Stop bit */
    _delay_us(15);
    data_hi();

    /* Ack */
    WAIT(data_lo, 50, 6);
    WAIT(clock_lo, 50, 7);

    /* wait for idle state */
    WAIT(clock_hi, 50, 8);
    WAIT(data_hi, 50, 9);

    idle();
    PS2_INT_ON();
    return ps2_host_recv_response();
ERROR:
    idle();
    PS2_INT_ON();
    return 0;
}
コード例 #3
0
ファイル: ps2.c プロジェクト: WonjoonLee/tmk_keyboard
/* receive data when host want else inhibit communication */
uint8_t ps2_host_recv_response(void)
{
    uint8_t data = 0;

#ifdef PS2_USE_INT
    PS2_INT_OFF();
#endif
    /* terminate a transmission if we have */
    inhibit();
    _delay_us(100);

    /* release lines(idle state) */
    idle();

    /* wait start bit */
    wait_clock_lo(25000);    // command response may take 20 ms at most
    data = recv_data();

    inhibit();
    return data;
}