Reference for register usage in order to write functional code

[Anonymous]

Looking at the C example code made me realized that I don't know how to write my own code. For example, the example generates the following C code:

   

    

 CapSense_CSD_Start();

    

    /* Initialize baselines */
    CapSense_CSD_InitializeAllBaselines();

    

    /*when return value is 1, perform while loop*/
    while(1u)
    {
        /* Check whether the scanning of all enabled widgets is completed. */
        if(0u == CapSense_CSD_IsBusy())
        {
            /* Update all baselines */
            CapSense_CSD_UpdateEnabledBaselines();

    

            /* Start scanning all enabled sensors */
            CapSense_CSD_ScanEnabledWidgets();
        }

    

        /* Display CapSense state using LEDs */
        CapSense_DisplayState();
        
    }

   

   

I can't figure out where the "1u" comes from that the while() function is using (thus where the "0u" that the if statement is using).

   

I assume that some register is loaded with a value that is checked by the while() loop as a result of the call to "CapSense_CSD_InitializeAllBaselines();" However, the capsense data sheet states that no value is returned as a result of the call to "CapSense_CSD_InitializeAllBaselines();" 

   

So, is there a reference that I can read that would provide this information?

   

What would lead me to write "while(1u);" if I didn't see this in the example?

   

What if I had other modules that required use of the what() function, how would I differentiate what source the "1u" would be used for the while loops?

   

Sincerely, Jeff

[Bob_Marlowe · Accepted solution]

Embedded processor projects usually have an infinite loop, so they perform their job as long as power is applied.

   

"1u" means nothing more that "Take the constant number 1 as an unsigned int"

   

Because any value except 0 (zero) has the meaning of "true" in C-language the statement

   

while(1u)

   

is the infinite loop.

   

I (personally dislike this writing. I use

   

#define forever 1

   

and a

   

while(forever)

   

which is quite more readable.

       

Bob

[Anonymous]

Bob,

   

Thanks a lot! That makes sense. As I noted, I thought it was a returned value and it isn't. This shows how important it is to comment code clearly.

       

Sincerely, Jeff