Midterm Solutions Fall 2011

PwnHero November 1st, 2011 COE 538 / BME 538 Midterm Name: _____________________________________ Student #: _______________________ Time: 90 min. Notes: 1. Closed book. 2. Write the answers in the space provided. 3. No question during the exam. State your assumptions. 1. Multiple Choice Questions (circle the number of the correct answer): a) What makes a microcontroller different from a microprocessor? [1 mark] i) Embedded data registers and stack pointer ii) Embedded ALU control unit and Program Counter (PC) iii) Embedded peripheral devices (I/O ports, ADC, etc.) iv) Embedded address and data bus to access memory b) Assume that the size of a memory addressable by a CPU is 64KBytes, and each memory location is 1 Byte. How many lines the address bus will contain: i) 8 lines ii) 10 lines iii) 12 lines iv) 14 lines v) 16 lines [1 mark] Show calculations that support your decision: 64Kbytes / 1 Byte = 64K = 64 × 210 = 26 × 210 = 216 Number of address lines = log2 216 = 16 [1 mark] c) Convert 2K to decimal representation: 2K = 2 × 210 = 2048 i) 10 bits ii) 11 bits iii) 1024 iv) 2048 v) 0x400 vi) 0x0400 [1 mark] 2. Fill in the underlined spaces in the following programs and identify the contents of the registers after the execution of the programs: a) Load Register A with $CA and add it with the hex value $36 located at $1100. Then store the result in the memory location at $1120. Fill in the underlined spaces in the program below: [3 marks] org $1500 ldaa #$CA ; load Register A with $CA adda $1100 ; add Reg.A with the hex value $36 located at $1100 staa $1120 ; store the result in the memory location at $1120 swi ; stop Show the 8-bit content of Reg.A and Condition Code Reg. after the execution of the program: [3 marks] Reg.A Bit # 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 CCR Bit code S X H I N Z V C Bit # 7 6 5 4 3 2 1 0 1 1 1 1 0 1 0 1 PwnHero.com