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Hi guys. I changed my board to C8051F226 already and i'm using a 32.768kHz external crystal. I have read the datasheet for the oscillator. But i do not understand this sentence, can someone please explain it to me?
"Crystal Oscillator Mode with divide by 2 stage."
The datasheet also recommend me to do the following:
1.Enable the external oscillator 2.Wait 1 ms 3.Poll for XTLVLD '0' ==> '1' 4.Switch to the external oscillator
I have done the 1st 2 steps, but i can't seem to poll for XTLVLD. When i compile, it says undefined symbol.
So the code above can be used?
Have you tested? Wouldn't a very simple test answer your question?
I tried it. and it works fine... thanks...
What does this sentence means?
Does this means that the crystal frequency is divided by 2?
I tried debugging my code... But the LCD only display "000 BPM". I took a sample of 5 seconds to get the pulses. I read through my code and found all of it logical (from my knowledge). Anyone can help me to find out the problem? Here is my timer and oscillator code:
MOV OSCXCN,#062H ; External Oscillator Control Register CLR A ; Clear value of Accumulator DJNZ ACC,$ ; Wait for DJNZ ACC,$ ; at least 1ms OX_WAIT: MOV A,OSCXCN ; Move data in OSCXCN to Accumulator JNB ACC.7,OX_WAIT ; Poll XTLVLD MOV OSCICN,#008H ; Internal Oscillator Control Register MOV IE,#8CH MOV IP,#04H SETB TCON.2 MOV TMOD,#10H MOV CKCON,#000H ;************* ;-Start Timer- ;************* START: MOV TH1,#0C9H MOV TL1,#50H ; Program timer to run for 5 seconds MOV R3,#00H SETB TR1 ; Start timer ;**************************** ;-Timer 1 Overflow Interrupt- ;**************************** T1_INT: CLR TF1 ; Clear overflow flag MOV TH1,#0C9H MOV TL1,#50H RETI ;********************** ;-External Interrupt 1- ;********************** EX_INT1: INC R3 ; Increment R3 MOV A,R3 ; Move data in R3 to Accumulator RETI
After this, i use a routine to convert binary HEX to ASCII and display.