Could someone explain to me the purpose of this bitwise operation?
Code:#define NVMC_CONFIG_WEN_Pos (0UL) /*!< Position of WEN field. */ #define NVMC_CONFIG_WEN_Msk (0x3UL << NVMC_CONFIG_WEN_Pos) /*!< Bit mask of WEN field. */
I mean, this is like moving to the left by zero positions the 0x3UL. I do not get it..
The purpose is to be able to change it to something that is not 0.
If it is zero then the actual operation will not appear in optimized code.
A little inaccuracy saves tons of explanation. - H.H. Munro
Hi John and thank you for your reply, still I do not understand it. Could you provide a real case example?
Do you know what a mask is?
In this case the mask is two bits in size and positioned with the rightmost bit of the mask at position 0 of the register.
But what if the rightmost bit of the mask needed to be at position 4?
In that case you just need to change NVMC_CONFIG_WEN_Pos to 4.
And if the mask needed to be 3 bits wide instead of 2, you could change NVMC_CONFIG_WEN_Msk to (0x7UL << NVMC_CONFIG_WEN_Pos).
That's one of the purposes of a define, to parameterize compile-time constants.
Last edited by john.c; 04-10-2022 at 02:03 PM.
A little inaccuracy saves tons of explanation. - H.H. Munro
