George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 ME 4447/6405 Microprocessor Control of Manufacturing Systems and Introduction to Mechatronics Instructor: Professor Charles Ume Lecture #11

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/ Write an assembly language program to clear the usable internal RAM in the MC9S12C32 [$0800 to $0DFF] Solution: Clear Locations $ $0DFF. ORG$1000 LDX#$0800 LOOPCLR$00,X INX CPX#$0E00 BNELOOP SWI END (NOTE: You should hand-assemble this program.) Homework Set #1 Solution

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Homework Set #1 Solution 2. Write a program to add even/odd numbers located in addresses $0000 through $00FE. Solution: (for adding odd numbers) ORG$1000 LDY#$ CD0000 LDX#$ CE0000 INDLDAA#$FF100686FF LDAB$00,X1008E600 BITB #$01100AC501 BEQEVEN100C2702 ABY100E19ED EVENINX STX$ E2000 EORA $ B82001 BNE IND101726ED SWI10193F END OR DECA 4A If you use this, then IND should be moved down to the next line st Time $2001: Acc A:

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Homework Set #1 Solution 2. Write a program to add even/odd numbers located in addresses $0800 through $0900. Solution: (for adding odd numbers) ORG$1000 LDY#$ CD0000 LDX#$ CE0800 INDLDAB$00,X1006E600 BITB #$011008C501 BEQEVEN100A2702 ABY100C19ED EVENINX 100E08 CPX#$ F8E0901 BNE IND101226ED SWI10143F END

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Write an assembly language program to find the largest signed number in a list of numbers stored in address $0020 thru $0029, and store it in $2000. Repeat for unsigned number. FIRSTEQU$0020 LASTEQU$002A ANSWREQU$2000 ORG$1000 LDX#FIRST LDAAFIRST STAAANSWR INXGoes with DECB. If DECB is removed, then LDAB#$0A LDAB must be removed NUBLDAA$00,X CMPAANSWR(A - ANSWR) BLENEXT; (signed)* *(Branches if 2's complement number in register A is less than or ORequal to the 2's complement number represented by ANSWR) BLSNEXT; (unsigned)****(Branch if lower or same, i.e, Branch if register A was lower or same as ANSWR) STAAANSWR NEXTINX CPX#LAST OR DECB BNENUB SWI END Homework Set #2 Solution

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Homework Set #2 Solution Continued Signed Example: #$3F (positive) #$F4 (negative) Convert Numbers to Decimal: #$F4 = % 's Comp#$0B = % 's Comp#$0C = % #$F4 = #$3F = % #$3F = #$3F is larger than #$F4 since is larger than Un-Signed Example: #$3F (positive) #$F4 (positive) Convert Numbers to Decimal: #$F4 = % #$F4 = #$3F = % #$3F = #$F4 is larger than #$3F since is larger than 63 10

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Homework Set #3 Solution 1. Write a subroutine to save the first 5 odd (8-bit) numbers pointed to by the x-register (passed in) onto the stack. Solution: SUB1LDAA#$05 PULY NEXTBRSET$00,X #$01 ODD INX BRANEXT ODDLDAB$00,X PSHB INX DECA BNENEXT PSHY RTS Note: For subroutine to execute in main program, a BSR or JSR command must be used in main program.

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Homework Set #3 solution 2. Write a program to output a square wave thru port S pin The output can be observed on the scope, and the period T of the wave should be measured. More than one period wave should be generated. The machine cycle time of the MC9S12C32 should be estimated. Draw the square wave.

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Homework Solution Cont’d Solution: ORG $2000 FCB$XX FCB$04 ORG$1000 LDAA#$04 STAA$024A LDAB#$04 CYCLELDAA$20013 STAA$02483 EORA#$041 STAA$20013 LDAA$20003 NEXTDECA1 BNENEXT3/1 DECB1 BEQ EXIT3/1 JMPCYCLE3 EXITSWI END OpcodePostbyteOperandAddress A024A 1005C B A7A D F7A B FD B E3F Configures PS2 as output. Outputs signal from PS2 T/2=Machine Cycle Time*[ COUNT*(1)+(COUNT-1)* ] (Note: Count = #$XX) Switch $2001(toggle) Delay Helps us to output two periods. (Note: BNE and BEQ take 3 machine cycles to execute if the branch is taken and one machine cycle if it is not taken)

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405

ME4447/6405 ASCII Character Codes ASCII – American Standard Code for Information Interchange ASCII assigns a hexadecimal ‘code’ to individual characters Examples: CharacterASCII ‘A$41 ‘E$45 ‘e$65(Note: Different codes for lower and upper case) ‘1$31 BS$08(Note: BS is Backspace. ) A microcontroller must send these codes to a display terminal in order for the terminal to display these characters.

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 ASCII Character Codes (continued) Hex to ASCII Conversion table from Programming Reference Guide Page 58

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 ASCII Character Codes An array of characters is called a string Example: character arrayStringASCII Representation ‘H ‘e ‘l ‘l ‘o “Hello”$48 $65 $6C $6C $6F (Note: CharacterASCII ‘H$48 ‘e$65 ‘l$6C ‘o$6F )

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405

ME4447/6405 Assembly Directive Types Assembly Control ORG, END Symbol Definition EQU Data Definition/Storage Allocation FCC, FCB, FDB, RMB, ZMB, BSZ, FILL Listing Control PAGE, OPT

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Assembly Control

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 ORG and END ORG : Store translated machine language instructions in sequence starting at given address for any mnemonic instructions that follow END: Stop translating mnemonics instructions until another ORG is encountered (Note: These were already discussed in Lecture 7)

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Symbol Definition

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 EQU EQU lets you refer to a number or an address as a variable name. Example: VALAEQU $10*LABEL VALA USED TO REFER TO $10 ORG $1000 LDAA #VALA*LOAD HEX NUMBER $10 IN ACCUMULATOR A LDAB VALA*LOAD CONTENT OF MEMORY LOCATION $10 *IN ACC. B SWI END Same As: VALAEQU $10*LABEL VALA USED TO REFER TO $10 ORG $1000 LDAA #$10*LOAD HEX NUMBER $10 IN ACCUMULATOR A LDAB $10*LOAD CONTENT OF MEMORY *LOCATION $10 IN ACC. B SWI END

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Data Definition/Storage Allocation

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 FCC FCC – Form Constant Character string FCC stores ASCII characters into consecutive bytes of memory. Any printable ASCII characters can be contained in the string. String is specified between two identical delimiters, which can be any printable ASCII character. First non-blank character after the string is used as a delimiter.

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 FCC Cont’d $0400 $0401 $0402 $0403 $0404 Address PrebyteOpcode Operand Example: ORG $0400 FCC “12345” Result

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 FCB FCB – Form Constant Byte FCB has one or more operands. Value of each operand is truncated to eight bits, and is stored in single byte of object program. Operand may be a numeric constant, character constant, a symbol or an expression. Multiple operands are separated by commas, and are stored in successive memory bytes.

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 FCB Cont’d Example: VALA EQU $10 ORG $0400 FCB $34,’A, $28AC, $0A,VALA $0400 $0401 $0402 $0403 Address PrebyteOpcode Operand AC 0A Result $040410

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 FDB FDB – Form Constant Double Byte FDB stores a double (two byte) word. May have one or more operands separated by commas. Operand may be a numeric constant, a character constant, a symbol, or an expression.

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 FDB Cont’d Example: ORG $0400 FDB $1234,’&,’G Note: ASCII value for & is $26 ASCII value for G is $47 $0400 $0401 $0402 $0403 $0404 Address PrebyteOpcode Operand $0405 Result

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 RMB RMB – Reserve Memory Byte RMB saves a place in memory for a number. Example: ORG $0400 XVAR RMB 2 *TWO MEMORY *LOCATIONS $0400 *and $0401 ARE *RESERVED FOR XVAR ORG $1000 LDD #$FFAA STD XVAR SWI END $0400 $0401 Address PrebyteOpcode Operand FF AA Result

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Question a student asked: What happens if you change the previous example to "XVAR RMB 3" instead of "XVAR RMB 2" ? What happens to the 3rd reserved byte when a 2 byte number is stored in XVAR? Modified Program: ORG $0400 XVARRMB 3 ORG $1000 LDD #$FFAA STD XVAR SWI END Answer: Remains unchanged

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 ZMB, BSZ ZMB – Zero Memory Byte and BSZ – Block Storage of Zero These directives fill a given number of memory locations with zero. Causes assembler to allocate a block of memory bytes, and each memory byte is assigned a value of zero. Both directives do the same thing. Number of bytes allocated is given in the operand field. Example: ORG $0400 ZMB #$02 BSZ #$02 $00 $01 Address PrebyteOpcode Operand 00 $02 $03 00 Result

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 FILL Fill given number of memory locations with any number. (Note: Fill uses one byte. If two bytes are specified, then it will truncate it and use LS Byte.) Example: ORG $0400 FILL #$FF, #$02 $00 $01 Address PrebyteOpcode Operand FF Result

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Question a student asked: What happens when the previous example is changed to "FILL #$9ABC, #$02" instead of "FILL #$FF,#$02"? What happens if you fill memory with a 2 byte number? Answer: FILL will just use the LS Byte Modified Example: ORG $0400 FILL #$9ABC,#$02 END (Note: There is no ”go 1000” on the screen since these are just assembly directives and not a program)

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Listing Control

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 PAGE The PAGE directive causes a page break in the list file. If no source listing is being produced, the PAGE directive will have no effect. The directive is not printed on the source listing.

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 OPT Allows for various options in assembly of a program, including generating a listing and counting instruction cycles. Options: nol-no output listing (default) l-do an output listing noc-no cycle number count (default) c-turn on cycle count using zero initial value contc-turn cycle count on, begin with last value cre-create a cross reference table (default anyway) RMB s-create a symbol table (default anyway) EQU Example: OPT l – Print source listing from this point

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Homework 3 Solution Write a subroutine to save the first 5 odd (8-bit) numbers pointed to by the x-register (passed in) onto the stack. Solution: SUB1LDAA#$05 PULY NEXTBRSET$00,X #$01 ODD INX BRANEXT ODDLDAB$00,X PSHB INX DECA BNENEXT PSHY RTS Note: For subroutine to execute in main program, a BSR or JSR command must be used in main program.

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Homework 4 solution Write a program to output a square wave thru port S pin 2. The output can be observed on the scope, and the period T of the wave should be measured. More than one period wave should be generated. The machine cycle time of the MC9S12C32 should be estimated. Draw the square wave.

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 Homework 4 Solution Cont’d Solution: ORG $2000 FCB$XX FCB$04 ORG$1000 LDAA#$04 STAA$024A LDAB#$04 CYCLELDAA$20013 STAA$02483 EORA#$041 STAA$20013 LDAA$20003 NEXTDECA1 BNENEXT3/1 DECB1 BEQ EXIT3/1 JMPCYCLE3 EXITSWI END OpcodePostbyteOperandAddress A024A 1005C B A7A D F7A B FD B E3F Configures PS2 as output. Outputs signal from PS2 T/2=Machine Cycle Time*[ COUNT*(1)+(COUNT-1)* ] (Note: Count = #$XX) Switch $2001(toggle) Delay Helps us to output two periods. (Note: BNE and BEQ take 3 machine cycles to execute if the branch is taken and one machine cycle if it is not taken)

George W. Woodruff School of Mechanical Engineering, Georgia Tech ME4447/6405 QUESTIONS???