Final Examination Solutions Fall 2003

PwnHero Ryerson University Department of Electrical and Computer Engineering ELE 538 – Microprocessor Systems Final Examination December 8, 2003 Name: __________________________ Student Number: ___________________ Section: __________ Time limit: 3 hours Examiners: K. Clowes, V. Geurkov Notes: a) Closed book except for 68HC11 Technical Data and/or Reference book. b) No questions during exam period. State any assumptions. c) Answer neatly all questions in the space provided. Unclear answers will not be accepted. d) Circle your professor’s name and hand in these sheets. e) Use standard symbolic names for any internal registers. 1. (3 marks) Disassemble the following memory dump into 68HC11 assembly instructions: 6000 DC 00 8B FE CB FD DD 00 Solution: ORG $6000 6000 DC 00 LDD $00 6002 8B FE ADDA #$FE 6004 CB FD ADDB #$FD 6006 DD 00 STD $00 2. (2 marks) How many memory chips are required to build a 1MB, 32-bit wide memory system using the 128K x 16 SRAM chips? Prove your answer. Solution: With x 16 organization memory chips, 2 chips will be required to build a 32-bit memory system. Two chips have a capacity of 128K x 32 bit = 512K x 8 bit = 512KB). Four chips will have a capacity of 1MB. 3. (5 marks) Given the following memory dump: 6020 67 FA 60 00 00 FF 43 66 78 00 FF 11 00 0A 00 FF 6030 54 6A 54 54 76 A5 51 34 F1 05 1F 53 01 4E 70 E1 fill in the blanks in the following table: (Solution in a bold case) Address Contents Assembly Code Acc. A Acc. B NZVC (CCR) X-re- gister Y-re- gister SP (Stack Pointer) PC (Progr. counter) 6200 CE 60 20 LDX #$6020 00 F2 000- 6020 FFFF 0041 6203 6203 EC 00 LDD 0,X 67 FA 000- 6020 FFFF 0041 6205 6205 83 00 45 SUBD #$45 67 B5 0000 6020 FFFF 0041 6208 6208 DD 56 STD $56 67 B5 0000 6020 FFFF 0041 620A 620A A6 07 LDAA 7,X 66 B5 0000