Bài giảng Vi xử lý - Chương 3: Vi điều khiển. Họ vi điều khiển 8051 (Phần 7)

eudo Code SyntaxOperator Precedence:	( )	~	@	*	/	%	+	-	>	>=	==	!=	&	^	|	&&	||	=	+=	-=	*=	/=	etc2021/10/2423T. L. Jong, Dept. of E.E., NTHUSuggested Pseudo Code SyntaxStructures:	Statement:	[do something]	Statement block:	BEGIN	[statement]	[statement]	END	WHILE/DO:	WHILE	[condition] DO	[statement]2021/10/2424T. L. Jong, Dept. of E.E., NTHUSuggested Pseudo Code SyntaxREPEAT/UNTIL:	REPEAT	[statement]	UNTIL	[condition]IF/THEN/ELSE:	IF	[condition]	THEN [statement 1]	(ELSE [statement 2])CASE/OF:	CASE [expression] OF	1: [statement 1]	2: [statement 2]	3: [statement 3]	.	.	n: [statement n]	[default]	END2021/10/2425T. L. Jong, Dept. of E.E., NTHUAssembly Language ProgrammingLabels	Use labels that are descriptive of the destination they representComments	Use comments wherever possible	Comment conditional jump instructions using a question similar to the flowchartComment Blocks	At the beginning of each subroutine: 	name of the sub, operations, entry conditions, exit conditions, name of other subroutines used, name of registers affected, etc.2021/10/2426T. L. Jong, Dept. of E.E., NTHU;***************************************************************************************;;INLINE	INPUT LINE OF CHARACTERS;	LINE MUST END WITH ;	MAXIMUM LENGTH 31 CHARACTERS INCLUDE ;;ENTER:	NO CONDITIONS;EXIT:	ASCII CODES IN INTERNAL DATA RAM;	0 STORED AT END OF LINE;USES	INCHAR, OUTCHR;;****************************************************************************************INLINE:	PUSH	00H	;SAVE R0 ON STACK	PUSH	07H	;SAVE R7 ON STACK	PUSH	ACC	;SAVE ACCUMULATOR	MOV	R0,#60H	;SET UP BUFFER AT 60H	MOV	R7,#31	;MAX LENGTH OF LINESTMENT:	ACALL	INCHAR	;INPUT A CHARACTER	ACALL	OUTCHR	;ECHO TO CONSOLE	MOV	@R0,A	;STORE IN BUFFERINLINE SUBROUTINE EXAMPLE2021/10/2427T. L. Jong, Dept. of E.E., NTHUINLINE:	PUSH	00H	;SAVE R0 ON STACK	PUSH	07H	;SAVE R7	PUSH	ACC	;SAVE ACCUMULATOR	MOV	R0,#60H	;SET UP BUFFER AT 60H	MOV	R7,#31	;MAX LENGTH OF LINESTMENT:	ACALL	INCHAR	;INPUT A CHARACTER	ACALL	OUTCHR	;ECHO TO CONSOLE	MOV	@R0,A	;STORE IN BUFFER	INC	R0	;INC BUFFER POINTER	DEC	R7	;DEC LENGTH COUNTER	CJNE	A,#0DH, SKIP	;IS CHAR = ?	SJMP	EXIT	;YES, EXITSKIP:	CJNE	R7,#0,STMENT	;NO, GET ANOTHER CHAREXIT:	MOV	@R0,#0	;END WITH NULL CHAR	POP	ACC	;RESTORE REGISTERS FROM	POP	07H	;STACK	POP	00H	RETINLINE SUBROUTINE EXAMPLE2021/10/2428T. L. Jong, Dept. of E.E., NTHU;********************************************************************************************; INCHR -	INput CHaRacter from serial port; enter:	no condition; exit:	ASCII code in ACC.0 to ACC.6; ACC.7 cleared; ctrl-C aborts;	to prompt;********************************************************************************************INCHR:	JB	X13_BIT,IN1	;if x13 installed, use interrupt flag RI	JNB	r_flag,$	;wait for receive_flag to be set	CLR	ET1	;begin “critical section”	CLR	r_flag	;>>> clear receive_flag and	MOV	A,r_buff	;>>> read receive_buffer	SETB	ET1	;end critical section 	SJMP	IN2	;	;if x13 is not installed, test RI flagIN1:	JNB	RI,$	;wait for receive interrupt RI	CLR	RI	;clear RI flag	MOV	A,SBUF	;done!IN2:	CLR	ACC.7	;clear parity bit (o error checking)	CJNE	A,#ETX, IN3	;if ctrl-C,	JMP	GETCMD	;warm startIN3:	RETINLINE SUBROUTINE EXAMPLE2021/10/2429T. L. Jong, Dept. of E.E., NTHU;********************************************************************************************; OUTCHR -	OUTput CHaRacter to serial port with odd parity added in;	ACC.7; enter:	ASCII code in ACC; exit:. 	Character written to SBUF; sent as ; all ;	registers intact;********************************************************************************************	RSEG	EPROMOUTCHR:	PUSH	A	NL:	MOV	C,P	;if x13 installed, use interrupt flag RI	CPL	C	;add odd parity	MOV	ACC.7,C	JB	X13_BIT,OUT1	;if x13 installed, use interrupt	JNB	t_flag,$	;wait for transmitter ready	CLR	ET1	;begin “critical section”	CLR	t_flag	;>>> clear flag and 	MOV	t_buff,A	;>>> load data to transmit	SETB	ET1	;end critical section 	SJMP	OUT2	;INLINE SUBROUTINE EXAMPLE2021/10/2430T. L. Jong, Dept. of E.E., NTHU	RSEG	EPROMOUTCHR:	PUSH	A	NL:	MOV	C,P	CPL	C	;add odd parity	MOV	ACC.7,C	JB	X13_BIT,OUT1	;if x13 installed, use interrupt	JNB	t_flag,$	;wait for transmitter ready	CLR	ET1	;begin “critical section”	CLR	t_flag	;>>> clear flag and 	MOV	t_buff,A	;>>> load data to transmit	SETB	ET1	;end critical section 	SJMP	OUT2	;	;if x13 is not installed, test TI flagOUT1:	JNB	TI,$	;wait for transmitter ready	CLR	TI	;clear TI flag	MOV	SBUF,A	;done!OUT2:	CLR	ACC.7	;remove parity bit	CJNE	A,#CR, OUT3	;if ?	MOV	A,#LF	;yes, add and send it	JMP	NL	;warm startOUT3:	POP	A	;no restore A and	JNB	p_bit,OUT4	;check if send to print	CALL	PCHAR	;yes, send to printer OUT4:	RET	;no, done and returnINLINE SUBROUTINE EXAMPLE2021/10/2431T. L. Jong, Dept. of E.E., NTHUAssembly Language ProgrammingSaving Registers on the Stack	Especially for nested subroutine calls, and building complex programs using subroutine building blocks. Avoid changing the working registers when returns.The Use of Equates	Defining constants with equates makes programs easier o read and maintain.The Use of Subroutines	Divide and Conquer – subdivide large and complex operations into small and simple operations. These small and simple operations are programmed as subroutines and used as building blocks of the large complex program.2021/10/2432T. L. Jong, Dept. of E.E., NTHUEnterChar !=0?Get a charFrom stringExitYesInc pointerNoOUTCHREnterTX bufferempty?Add odd parityTo characterExitYesWrite characterTo transmitterNoClear flagClear parity bitOUTSTROUTCHROUTSTR SUBROUTINE EXAMPLE2021/10/2433T. L. Jong, Dept. of E.E., NTHUPseudo code for OUTCHROUTCHR (char)	[put odd parity in bit 7]	REPEAT	[test transmit buffer]	UNTIL	[buffer empty]	[clear transmit buffer empty flag]	[move char to transmit buffer]	[clear parity bit]RETURN ()Pseudo code for OUTSTROUTSTR (pointer)	WHILE	[(char = @pointer) != 0] BEGIN	OUTCHR(char)	[increment pointer]	ENDRETURN()OUTSTR SUBROUTINE EXAMPLE2021/10/2434T. L. Jong, Dept. of E.E., NTHU;****************************************************************************************;OUTCHR:	OUTPUT A CHAR IN ACC W. ODD PARITY VIA ;	SERIAL PORT;ENTER:	NO CONDITION, ASCII CHAR IN ACC;EXIT:	ASCII CODE W. ODD PARITY SENT OUT & ACC.7=0;***************************************************************************************OUTCHR:	MOV	C,P	;PUT PARITY BIT IN C FLAG	CPL	C	;CHANGE TO ODD PARITY	MOV	ACC.7,C	;ADD TO CHARAGAIN:	JNB	TI,AGAIN	;TX EMPTY?	CLR	TI	;YES, CLEAR FLAG AND	MOV	SBUF,A	;SEND OUT CHARACTER	CLR	ACC.7	;STRIP OFF PARITY BIT AND	RET	;RETURN;****************************************************************************************;USES	OUTCHR;OUTSTR:	MOV	A,@DPTR	;GET CHARACTER	JZ	EXIT	;IF 0, DONE AND EXIT 	CALL	OUTCHR	;OTHERWISE SEND IT	INC	DPTR	;INC POINTER	SJMP	OUTSTREXIT:	RETOUTSTR SUBROUTINE EXAMPLE2021/10/2435T. L. Jong, Dept. of E.E., NTHUAssembly Language ProgrammingProgram OrganizationEquatesInitialization instructionsMain body of programSubroutinesData constant definitions (DB and DW)RAM data locations defined using the DS directive2021/10/2436T. L. Jong, Dept. of E.E., NTHUTools & Techniques for Program DevelopmentThe Development Cycle2021/10/2437T. L. Jong, Dept. of E.E., NTHUSpecifying SoftwareUser interface: how the user will interact with and control the systemDetail system operations below the user level – independent of user interfaceModularized system function with inter-module communicationInterrupt driven, ISR, time-critical subroutine2021/10/2438T. L. Jong, Dept. of E.E., NTHUDesigning SoftwareFlowchartsPseudo codeEditing and TranslationAssemble time errors checking: syntax errors only2021/10/2439T. L. Jong, Dept. of E.E., NTHUPreliminary TestingRun time errors will not appear until the program is executed by a simulator or in the target system.Debugger – a system program that executes a user program for the purpose of finding run-time errors.Debugger can set breakpoints, single-stepping, examine and modify registers, memories, etc. during program execution2021/10/2440T. L. Jong, Dept. of E.E., NTHUHardware DevelopmentSpecifying hardware: assign quantitative data to system functions, physical size/weight, CPU speed, memory, I/O ports, optional features, etc.Designing Hardware: breadboarding, wire-wrapping, PCB layoutpractice makes perfect2021/10/2441T. L. Jong, Dept. of E.E., NTHUHardware DevelopmentPreliminary Testing: Visual checks – before power appliedContinuity checks – ohmmeter check each connecting wire, IC pin to IC pinDC measurements – no ICs, DC voltages variedAC measurements – IC installed, verify clock signals, and so onFunctionality Testing – drive RESET w a low f (1 kHz) square wave, write test software or monitor program to debug each function of the hardware board2021/10/2442T. L. Jong, Dept. of E.E., NTHUDetailed Steps in the Development Cycle2021/10/2443T. L. Jong, Dept. of E.E., NTHUIntegration and VerificationHardware Software Integration testSoftware Simulation – simulatorHardware Emulation – hardware emulator or in-circuit emulator (ICE)Execution from RAM – effective & simple testing for software in the target system2021/10/2444T. L. Jong, Dept. of E.E., NTHUIntel Hexadecimal FormatFieldBytesDescriptionRecord mark1“:” indicates start-of-recordRecord length2Number of data bytes in recordLoad address4Start address for data bytesRecord type200 = data record; 01 = end recordData bytes0-16dataChecksum2Sum of all bytes in record + checksum = 02021/10/2445T. L. Jong, Dept. of E.E., NTHUIntel Hexadecimal Format2021/10/2446T. L. Jong, Dept. of E.E., NTHUIntegration and VerificationExecuting from EPROM – firmware burnt in EPROM using EPROM writerExecuting from on-chip flash (8952), EPROM (8752), EEPROM, (OTP, MTP) using Universal Programmer/WriterThe Factory Mask ROM – for mass productionExecuting from SRAM downloaded from host into the SBC-512021/10/2447T. L. Jong, Dept. of E.E., NTHUThe Development Environment2021/10/2448T. L. Jong, Dept. of E.E., NTHU