We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
hi there, i have struct with the problem.in the multiplexing of the 7-segment display. as i complited the 7-segment display multiplexing. prog.is working properly. but when i moved to the next some advance step it give's the above msg. i think the problem is in the variable passing between function. because as i try to pass the local data to globle side
can any one explain me the passing the value's between two function. the function returning the value is in the main function and the function which recive's the value is out of the main function the function which recive's the value is out of the main function is the part of the interrupt routine the function which sending or returning the value is the part of main function
"can any one explain me the passing the values between two function"
This is standard 'C' - nothing specifically to do with Keil at all. Therefore, any 'C' textbook should be able to help you.
See: c-faq.com/.../srcfiles.html and the associated links
thank's andy but when i face the problem i done the each and every thing for which i capable but i can not get the way to of it. here i providing the sample or small model fo the problematic code hope u will help me
unsigned int i,j,k,l,a; unsigned int sft = 1; void disp(unsigned int a); unsigned int go (void); /*interrupt setting (routine)***/ void TMR_0(void) interrupt 1 { TF0 = 0; TR0 = 0; TH0 = 0xAA; disp(unsigned int); TL0 = 0x00; TR0 = 1; } void disp(unsigned int a) { sft = a; DECOD1 = 0; /* 7-segment 1st display */ DECOD2 = 0; DECOD3 = 0; P0 = number_code[i]; if(sft != 1) {disp_wait();} blink(); } /**** main prog******/ void main() { P0 = 0x3f; /* initial port setting */ P1 = 0xff; P2 = 0xf8; P3 = 0xff; IE = 0x82;/*timer and interrept setting*/ TMOD = 0x01; TH0 = 0xAA; TL0 = 0x00; TR0 = 1; while(1) { unsigned int go(); } } unsigned int go() { /***shift key press identification *********/ if(KEY2_SFT == 0) { sft++; sft_wait(); KEY2_SFT = 1; if(sft > 4) {sft = 1;} a = sft; return(a); }
unnessary code is omited can any one suggest the nessary change in this code.
Where, precisely, does error C141: syntax error near 'unsigned' occur in this code?
/*interrupt setting (routine)***/
void TMR_0(void) interrupt 1 { TF0 = 0; TR0 = 0; TH0 = 0xAA; disp(unsigned int); at this point TL0 = 0x00; TR0 = 1; } </prr>
Well, the error should be obvious!
But we've all been at that point of staring at a piece of code for so long that we can no longer see the wood for the trees!
So, back to basics: how do you call a function in 'C'? How do you supply parameters when you call a fucntion in 'C' - what should go within the parentheses...?
What is the value or variable that you actually want to pass to the display() function at this point...?
unsigned int go() { /***shift key press identification *********/ if(KEY2_SFT == 0) { sft++; sft_wait(); KEY2_SFT = 1; if(sft > 4) {sft = 1;} a = sft; i want to pass this value return(a); }
/*********************************************/
disp(unsigned int); at this point
OK, let's take this one step at a time.
How do you pass a parameter to a function when you call it?
Insert an appropriate call to my_function in the code below, passing fred as its parameter:
void my_function( unsigned int x ); // function prototype void main( void ) { unsigned int fred; // Insert a call here }
void disp(unsigned int a); //it going to used in the interrupt unsigned int go (void); //going to used in main function void main() { P0 = 0x3f; /* initial port setting */ P1 = 0xff; P2 = 0xf8; P3 = 0xff; IE = 0x82;/*timer and interrept setting*/ TMOD = 0x01; TH0 = 0xAA; TL0 = 0x00; TR0 = 1; while(1) { unsigned int go(); } }
void my_function( unsigned int x ); // function prototype void main( void ) { unsigned int fred; my_function(unsigned int);// Inserted a call here }
OK. you are struggling with the basics of calling a function in 'C'.
You need to set aside your code, and concentrate just on the basic concept of calling a function - any function - and passing a parameter to it.
There is no point in trying to go any further before you have mastered this fundamental concept.
Hint: Look-up "formal" and "actual" parameters in your 'C' textbook.
Then try the exercise again:
Insert an appropriate call to my_function in the code below, passing fred as its parameter: then
void my_function( unsigned int x ); // function prototype void main( void ) { unsigned int fred; my_function(unsigned int fred);// Inserted a call here }
here the "actual" parameter is fred
and the "formal" parameter is x
Did you compile it? What did the compiler say?
What does your 'C' text book say about calling functions? Specifically, what should go inside the brackets?
"here the 'actual' parameter is fred and the 'formal' parameter is x"
Yes - good!
Now, what should go inside the brackets in the call to the function?
as far as this e.g. concern the value assigned to fred is going to used in the my_function.i.e. it passing to through the basket and used by the function
"the value assigned to fred is going to used in the my_function"
Yes, so if you want the value of 'fred' to be passed through to the function, what do you put inside the brackets in the function call?
Hint: the type of 'fred' has already been defined in the line
unsigned int fred;
So the compiler already knows what type 'fred' is - you don't have to specify it again, do you...?