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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?
Design an interface between the 68000 and a multiplexed bus you may specify your won multiplexed bus for the purpose of this question.
What are the advantages and disadvantages of multiplexed address data bus over the system used by the 68000?
What are the reasons for address registers? What are the effects of this on both the programmer and the hardware designer?
Why then must the 68000's RESET* input be asserted for at least 100 rns after the initial application? Why do RESET* and HALT* have O/D (open drain) outputs?
Design a circuit to permit a single bus cycle at a time to be executed. The HALT* line must normally be held in its active-low state and be negated long enough.
What are the relative merits of the asynchronous memory access and the synchronous memory access?
You should use the minimum number of registers in your subroutine. Draw a memory map of the stack during the execution of your subroutine.
Why is C so popular as a systems programming language in applications such as embedded microprocessor systems?
Write a subroutine called, ADDABC, that performs the operation c : A + B. The three variables A, B, and C are all word (i.e., 16-bit) values.
Write a subroutine, call it, and pass parameters X, Y, and Z on the stack. Test your program by using the 68000 simulator's debugging facilities.
Write a 68000 subroutine to perform the search, and then write a 68020 subroutine to perform the same action (making the best use of the 68020's facilities).