Hello i want to write a byte to P0.24 ~~P0.31 without affecting other pins on Port P0 What i shuld i do ? Guide me thank you

[liuyanfeng]

Hello i want to write a byte to P0.24 ~~P0.31 without affecting other pins on  Port P0   What i shuld  i  do ? Guide me  thank you

[ovrebekk]

Hi 

In that case you should use a bitmask to mask out the bits that you want to change. 

Something like this:

#define MY_PINS_POS  24
#define MY_PINS_MASK 0xFF000000
#define OTHER_PINS_MASK (~MY_PINS_MASK)

// Change P0.24-P0.31 only
uint8_t my_data = 12;
NRF_P0->OUT = (NRF_P0->OUT & OTHER_PINS_MASK) | ((uint32_t)my_data << MY_PINS_POS);

Best regards
Torbjørn

[liuyanfeng]

static void SPI_WriteDat8Bit( uint8_t DByte )
{
    NRF_GPIO_Type *p_reg=NRF_P0;

    uint32_t value=0;    
 
    value = nrf_gpio_port_out_read(p_reg);

    value &= 0x00FFFFFF;

    value |= (DByte<<24);

    nrf_gpio_port_out_write(p_reg, value);

}

Can I do this? The value is read from port 0, and then p24 to 31 is cleared and assigned.

[liuyanfeng]

ovrebekk  ,thanks your reply

[ovrebekk]

Hi 

You welcome

The code below looks correct. 

Best regards
Torbjørn