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What is a double bus fault and why is it described as fatal? If you were a systems designer, what would you do to attempt to make your system hacker-proof?
Why does the location of the 68000s reset vectors cause the system designer so many problems? What is the exception with the highest priority?
After an exception, the program counter is saved on the supervisor stack. What does this value of the PC point at?
What are the differences between TRAPS, illegal instruction exceptions, and line A and line F exceptions?
You decide to use the 68000's line 1010 emulator trap. Show how you would do this. Remember that the instruction will have the form.
Write a trace exception handling routine that displays the contents of registers whenever an instruction is executed that falls between two addresses.
What does context switching mean, and how can it be implemented (making best use of the 68000's features)?
Each time the button is depressed, IRQ7* is pulled low. Why is it necessary to employ a debounced switch?
Why can you locate some of the additional vectors in the 68000's exception vector table at locations marked unimplemented, reserved?
Design a circuit to generate an interrupt on IRQ1* every T seconds, provided that interrupts IRQ2*-IRQ7* have not been asserted during the previous T seconds.
A print spooler prints one or more files as background jobs while processor is busy executing a job. `Design a basic print spooler that will print a file.
Design the necessary logic interface to make this peripheral look like a 68000-series component.
All ItO had to be polled. Why do you think that this decision has been taken? Hint: Railway control is a high-security application of computers.
Design a hardware filter that would prevent any peripheral supplying a number in the range 0-63 during an JACK cycle.
What is a spurious interrupt and how is it generated? What is the difference between an uninitialized interrupt and a spurious interrupt exception?
Why is RAS*-only refreshing now less popular than CAS*-before-RAS* refreshing? Why does the CAS*-only refresh make it easy to design a refreshing system?
Why must DRAMs be refreshed, and how may a refresh operation be carried out? What effect does it have on the design of DRAM systems?
Why is the value of tRcD (RAS* low to CAS* low) a pseudo maximum value? What factors determine the minimum and maximum values of tRcD?
How is an EPROM able to store data in the absence of electrical power? What is the primary address range of this block of EPROM?
What is the maximum read cycle access time that a memory component can have if it is to be employed in an 8-MHz system with no wait states?
Microprocessors like 68000 use address and data buses and special-purpose dedicated control pins. What are advantages and disadvantages of such an arrangement?
Design an asynchronous bus interface for the 68000 that does not use separate UDS* and LDS* data strobes.
Why does the 68000 require only one address strobe, AS*, but two data strobes, UDS* and LDS*? Would a single pair of data strobes be sufficient?
What is the meaning of data setup time and data hold time? Can either of these values be zero? Can they be negative?
What are the advantages and disadvantages of the protocol diagram as a design tool? That is, what does each diagram reveal, and what does it hide?