July 2008
Intermediate to advanced
544 pages
16h 52m
English
Content preview from Computers as Components, 2nd Edition
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
Start your free trial
148 CHAPTER 3 CPUs
QUESTIONS
Q3-1 Why do most computer systems use memory-mapped I/O?
Q3-2 Write ARM code that tests a register at location ds1 and continues execution
only when the register is nonzero.
Q3-3 Write ARM code that waits for the low-order bit of device register ds1 to
become 1 and then reads a value from register dd1.
Q3-4 Implement peek( ) and poke( ) in assembly language for ARM.
Q3-5 Draw a UML sequence diagram for a busy-wait read of a device.The diagram
should include the program running on the CPU and the device.
Q3-6 Draw a UML sequence diagram for a busy-wait write of a device.The diagram
should include the program running on the