EE 3750 — Test 2 Wed., April 21, 2004 — Open Book and Notes For all problems: state any assumptions made; include comments as needed to make assembly language instruction sequences clear. 1. (30 pts) Write an 8086 instruction sequence to do the following. Let GRAY be a word variable in memory that holds an unsigned double-word value in two consecutive words. Shift the double-word at GRAY to the right by 5 bits. 2. (10 pts) Let ACALL and ARET denote alternative implementations of the CALL and RET instructions that swap the return address with a new pair of registers, IPX and CSX, instead of pushing and popping the return address to and from the stack. (That is, ACALL swaps IP and CS with IPX and CSX, then loads the IP and CS values for the procedure; ARET swaps IP and CS with IPX and CSX.) Explain what types or sequences of procedure calls and returns that CALL and RET can do that ACALL and ARET also can do. Explain what types or sequences of procedure calls and returns that CALL and RET can do that ACALL and ARET
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The Return, 16550 UART, Universal asynchronous receiver/transmitter