8051 labs

MY_SECOND_TIMER SEGMENT CODE

CSEG AT 0
JMP startC

RSEG MY_SECOND_TIMER
 startA:
	MOV R3, #0h
	MOV R0, #20
	DELAY:
		MOV TMOD,#00000001B // Sets Timer 0 to MODE1 (16 bit timer)
		MOV TH0,#76 // Loads TH0 register with 76
		MOV TL0,#01 // LOads TL0 register with 01
		SETB TR0 // Starts the Timer 0
	HERE:
		JNB TF0,HERE // Loops here until TF0 is set (ie;until roll over)
		CLR TR0 // Stops Timer 0
		CLR TF0 // Clears TF0 flag
	DJNZ R0,DELAY
	INC R3
	MOV P2,R3
	SJMP startA


//Frequency 11.0592MHz=12 pules
//1 clock pulse =11.0592MHz/12
//F =0.921 MHz
//Time delay=1/F
//T=1/0.92MHz
//T=1.080506 us (for ‘1’ cycle)
//1000us=1MS
//1000ms=1sec

// 1 second delay = 1000000/1.080806 ~= 925235 cycles
// but timer can count 65535 cycles max :(
// so grab 50ms and iterate it 20 times
//


 startB:
	MOV R3, #0
	MOV R0, #2
	MOV P2, #00h
	wait:
		MOV A,P1
		CJNE A,#11111110B,wait
		//CJNE - Compare and Jump if not Equal
		//JNZ wait // Loops here until P1.0 is set
		//JZ - Jump if Accumulator Zero
		//JNZ - Jump if Accumulator not Zero

	DELAYB:
		MOV TMOD,#00000001B // Sets Timer 0 to MODE1 (16 bit timer)
		MOV TH0,#76 // Loads TH0 register with 76
		MOV TL0,#01 // LOads TL0 register with 01
		SETB TR0 // Starts the Timer 0
	HEREB:
		JNB TF0,HEREB // Loops here until TF0 is set (ie;until roll over)
		CLR TR0 // Stops Timer 0
		CLR TF0 // Clears TF0 flag
	DJNZ R0,DELAYB
	INC R3


	MOV A,P1
	CJNE A,#11111110B,startB
	// JNZ startB // if button is clicked continue set diod if not, start again

	MOV P2,R3
	SJMP DELAYB


startC:
	MOV R3, #0
	MOV R0, #2
	MOV P2, #00h

	checkButtonBeforeStart:
		MOV A,P1
		CJNE A,#11111110B,checkButtonBeforeStart

		//CJNE - Compare and Jump if not Equal
		//JNZ wait // Loops here until P1.0 is set
		//JZ - Jump if Accumulator Zero
		//JNZ - Jump if Accumulator not Zero

	DELAYC:
		MOV TMOD,#00001001B // Sets Timer 0 to MODE1 (16 bit timer)
		MOV TH0,#76 // Loads TH0 register with 76
		MOV TL0,#01 // LOads TL0 register with 01
		SETB TR0 // Starts the Timer 0

	HEREC:
		MOV A,P1
		CJNE A,#11111111B,settimeron
		JMP settimeroff
		settimeron:
			MOV P3, #00000100B
			JMP go
		settimeroff:
			MOV P3, #00000000B
		go:
		JNB TF0,HEREC // Loops here until TF0 is set (ie;until roll over)
		CLR TR0 // Stops Timer 0
		CLR TF0 // Clears TF0 flag
		DJNZ R0,DELAYC

	INC R3
	MOV P2, R3
	JMP checkButtonBeforeStart
END