List three examples of mass-storage devices.

List the functional parts of a computer.

What are tristate buffers?What are they used for?

Give several examples of I/O devices.

What is memory-mapped I/O?

What is a bus? What is the function of the data bus? Of the address bus?

What is an embedded computer?

The address bus of a computer is 16 bits wide and the data bus is 32 bits wide. How many bytes does the memory potentially contain?

Define the terms microprocessor, microcomputer, and microcontroller.

Explain the difference between Harvard computer architecture and von Neumann computer architecture.

What is RAM? List two types. Is it useful for storing programs in embedded computers? Explain.

What is ROM? List four types. Is it useful for storing programs in embedded computers? Explain.

List three examples of mass-storage devices.

Which type of memory is least expensive per unit of storage? (Assume that many megabytes of capacity are required.)

How many memory locations can be addressed if the address bus has a width of 32 bits?

Which type of memory would be best in the controller for an ignition system for automobiles?

When might we choose EEPROM rather than mask-programmed ROM?

What types of memory are volatile? Nonvolatile?

List the elements that are potentially found in a microcomputer-based control application.

What is a sensor? Give three examples.

What is an actuator? Give three examples

Explain the difference between a digital sensor and an analog sensor. Give an example of each.

List five common household products that potentially include an MCU.

List two potential applications of MCUbased control or instrumentation in your field of specialization.

What is an A/D? Why might one be needed in a MCU-based controller?

What is a D/A? Why might one be needed in a MCU-based controller?

What is polling? What is an interrupt? What is the main potential advantage of interrupts versus polling?

What is the function of the A, B, and D registers of the CPU12?

What is the function of the program counter register? Of the condition-code register?

What is a stack? What is the stack pointer used for?

What is a LIFO memory?

Suppose that initially the contents of the registers are A:07 B:A9 SP:004F X:34BF and that memory locations 0048 through 004F initially contain all zeros. The commands PSHA, PSHB, PULA, PULB, PSHX are then executed in sequence. List the contents of the registers A, B, SP, and X, and the memory locations 0048 through 004F after each command is executed.

Suppose that initially the contents of the registers are A:A7 B:69 SP:004E Y:B804 and that memory locations 0048 through 004F initially contain all zeros. The commands PSHY, PSHB, PULY, PSHA are then executed in sequence. List the contents of the registers A, B, SP, and X and the memory locations 0048 through 004F after each command is executed.

Write a sequence of push and pull commands to swap the high byte and low byte of the X register. After the sequence of commands is executed, the contents of the other registers should be the same as before.

For each part of this problem, assume that the X register contains 2000 and the A register initially contains 01. Name the type of addressing and give the content of A after each instruction listed next. The contents of memory are shown in Figure P8.34. a. LDDA $2002 b. LDDA #$43 c. LDDA $04 d. LDDA 6,X e. INCA f. CLRA g. LDAA $2007 h. INX 0000 0001 0002 0003 0004 0005 0006 0007 01 FA 9B 61 9A B6 73 41 2000 2001 2002 2003 2004 2005 2006 2007 37 AF 20 07 20 00 FF F3 Figure P8.34

Suppose that the contents of certain memory locations are as shown in Figure P8.34. Furthermore, for each part of this problem, the initial contents of the CPU registers are: (D) = $0003, (X) = $1FFF, and (Y) = $1000. Name the type of addressing and determine the contents of registers D,X,andY after each of these instructions is executed: a. ADDB $1002,Y b. LDAA B,X c. LDAB 7,+X d. LDX [$1004,Y] e. LDAA [D,X]

a.Assume that the A register initially contains FF and that the program counter is 2000. What is the address of the instruction executed immediately after the branch command? The content of memory and the corresponding instruction mnemonics are shown in Figure P8.36(a). b. Repeat for Figure P8.36(b). c. Repeat for Figure P8.36(c). 2000 2001 INCA BMI $11 2002 2003 (b) 42 2B 11 2000 2001 TSTA BMI $07 2002 2003 (a) 97 2B 07 2000 2001 TSTA BMI $0A 2002 2003 (c) 97 2B F6 Figure P8.36

Give the machine code for each of the following instructions: a. CLRA b. ADDA $4A c. ADDA $02FF d. BNE -$06 e. ADDA #$0D How many memory locations are occupied by each instruction?

Find the content of the A register after each instruction as the following sequence of instructions is executed: LDAA #$01 ADDA #$F1 CLRA Is the N bit of the condition-code register set or clear? Is the Z bit of the condition-code register set or clear?

a. Suppose that the content of A is 43. Find the content of A after the instruction ADDA #$05 is executed. b. Suppose that the content of A is FA. Find the content of A after the instruction ADDA #$0F is executed. (In this case, overflow occurs.)

Assume that the content of A is $A7 and that the content of B is $20. Find the contents of A and B after the MUL instruction is executed. (Hint: The MUL instruction assumes that the contents of A and B are unsigned integer values.)

Write an assembly-language program starting in location 200 that multiplies the content of the A register by 1110 and stores the result in memory locations $FF00 and $FF01, with the most significant byte in location $FF00. The processor should then be stopped.

Write an assembly-language program starting in location 0400 that stores 00 in location 0800, 01 in 0801, 02 in 0802, 03 in 0803, and then halts the processor.

Write a subroutine called DIV3 that divides the content of A by three. Assume that the initial content of A is a positive integer in twos-complement form. On return from the subroutine, the quotient should reside in B and the remainder in A.

Consider the following assembly-language code for the CPU12: ; PROBLEM 8.44 ; ORG $0600 START LDAA #$07 LDAB #$AF STD $0609 STOP END Describe the effect of each line of this code and list the contents of memory locations 0600 through 060A after the code has been assembled and executed.

Write a subroutine called MUL3 that rounds the content of A to its nearest integer multiple of 3. Assume that the initial content of A is a positive integer in twos-complement form. Memory location $0A can be used for temporary storage. Include comments in your source code to explain the program and its operation to human readers. (Hint: Repeatedly subtract 3 until the result becomes negative. If the result is 3, the original content of A was a multiple of 3 and should not be changed. If the result is 2, the original content of A was one plus an integer multiple of 3, and we should subtract one from the original number to obtain the nearest multiple of 3. If the result is 1, the original content of A is 2 plus an integer multiple of 3, and we should add 1 to the original number to obtain the nearest multiple of 3.)

Suppose that register B contains a twodecimal-digit BCD number n. Write a subroutine called CONVERT that replaces the content of register B by its binary equivalent. The content of the other registers (except the program counter) should be unchanged at the completion of the subroutine. Memory locations $1A, $1B, and $1C can be used for temporary storage. [Hint: We need to separate the upper nibble (four bits) of n from its lower nibble. This can be achieved by shifting n four bits to the left, with the result appearing in the D register. Shifting by four bits to the left is accomplished by multiplying by 24.]