Un PIC de teorie şi un PIC de practică

[ratza]

Nimic nu e gratis.

Din p?cate e groaznic de adev?rat. Orice solu?ie e un compromis, dar ca vitez? de execu?ie asta e cea mai rapid?. Eu am avut nevoie de un sinus extrem de precis, din Hz în Hz, începînd de la 0 pîn? la 200Hz, realizat din 256 de e?antioane ?i eram limitat groaznic de timp, sistemul trebuind s? mai fac? o gr?mad? de alte porc?rii. Nici nu mai vreau s?-mi aduc aminte de ce probleme de jitter am avut ?i cum mi-am stors creierii încercînd s? g?sesc gre?elile din cod f?r? debugger, doar cu un am?rît de osciloscop. Detest programarea.

[NumLock]

Îmi spui acum cum fac asta recursiv (cu detalii) ?

Ar fi fost politicos sa bagi si un "te rog" , dar hai sa zicem ...

Îmi cer scuze, m? gr?beam ?i am uitat ?i cuvintele magice . Merci de informa?ii (?i ?ie ?i lui @ratza) . O s? încerc algoritmul în Excel a?a cum ai zis.

[NumLock]

Salut,

 

Am nevoie de pu?in ajutor ?i de explica?ii. Nu ?tiu dac? am 'tradus' corect codul din acest document PDF, pentru conectarea unui microcontroler PIC la un MT8880/CM8880 (PIC Program I Listing: DTMF Dialing).

 

Cred c? nu am în?eles 100% ace?ti pa?i:

 

(1) Put the data pins into output mode - movlw 0; movwf TRISA

(2) Write the data to the bus - scriu în primul nybble al PORTB un numar

(3) Set up RS0: 0 = write data; 1 = write instructions - ?

(4) Clear the RW bit to request a write - bcf PORTB, 5

(5) Clear CS to activate the CM8880 - bcf PORTB, 6

(6) Set CS to terminate the write operation and deactivate the CM8880 -bsf PORTB, 6

generate:		bsf	STATUS,  RP0		movlw	.255			; All bits high to deselect MT8880		movwf	TRISB		movlw	talk			; Set port to output		movwf	TRISB		call 	        delay			; Wait for things to settle down		movlw	dials			; Set control register for dialing		movwf	cntrl			call 	        set_controls 	; Write settings to control registers		clrf	        digit			; Clear the digit counter to 0				movf	digit,  W		        ; Now, put the digit number into W                                                       		call	dial_digit			; Dial the digit stored in W		hold:		bsf	STATUS,  RP0		; Select Bank1		movlw	listen		movwf	TRISB			; Set port to input		call	get_status		bsf	STATUS,  RP0		btfss	stats,  xm_rdy		; If transmitter's not ready, wait here		goto	hold		movlw	talk			; Restore port to output.		movwf	TRISB		goto	 generate		; Generates a brief delay to allow MT8880 to get settled after power-on.delay: 		movlw	.64		movwf	temploop		nopdecfsz	temp,  f			; Loop 257 times		goto	loop		return				; Return; Accepts data to be written to the pair of four-bit control registers in; the variable "cntrl." Data for register 1 must be in the lower nybble;; register 2 in the upper nybble.set_controls:		movf		cntrl,  W		; Get the control value				andlw		b'00001111' 	; Strip upper four bits			iorlw		b'00011000'	        ; Set register-select, clear CS, set RS2.		movwf	PORTB		; Write to output, (CS low).		bsf		PORTB,  CS	        ; Deselect to complete the 1st write.				swapf		cntrl,	W	        ; Get nybble-swapped control value.		andlw		b'00001111' 	; Strip upper four bits		iorlw		b'00010000' 	; Set register-select, clear CS.		movwf	PORTB	        ; Write to output, (CS low).		bsf		PORTB,  CS	        ; Deselect to complete the 2nd write.		return; Dials a DTMF digit represented by the lower four bits of the; W register. Converts a value of "0" to "10" in accordance with; the DTMF encoding scheme.dial_digit:		andlw		.15		; Strip MSB, update z flag in the process		movf		W,	1	; If w=0, change it to 10 for proper..		btfss		STATUS,  Z	; ..DTMF encoding		movlw	.10							movwf	PORTB		; Write to output		BSF		PORTB,   CS	; Terminate the write		return		; Gets the contents of the MT8880's status register and stores 'em; to the variable "stats." The port TRIS (data direction) must; be set to input before calling this routine.get_status:		bcf		STATUS,	 RP0		; Select Bank0		bsf		PORTB,  	 RW		; Set to read		bsf		PORTB,	 RS		; Select the status register		bcf    	PORTB, 	 CS		; Activate chip				movlw	.15			        ; Bit mask for 4-bit data		movlw	stats					movf		stats,	 W					andlw		PORTB			; Get lower 4 lsbs of rb (data)					bsf		PORTB,  CS		        ; Deselect chip		return

Numa bine.

[NumLock]

+Care este diferenta intre PIC16F84A-04/P - PIC16F84A-20/P ? Frecventa (4MHz - 20Mhz)?

[francezu]

Da,este vorba de frecventa maxima de lucru.Vezi datasheet pagina 85.