Memory?mapped I/O may fail to operate in a system with cache memory. Why? What is the remedy?
What will be an ideal response?
In a memory?mapped system, data is transferred between a peripheral and memory directly. Since the processor
and a program are not involved and data is transferred using special DMA hardware, the data transfer can be very
fast. However, suppose the system has a cache memory and the I/O data region is currently cached. If a DMA
device stores data in memory, it will be out?of?step with the cached data at the same addresses. The cached data
will be stale and the new data not read. It is necessary to invalidate the cached data or to mark the I/O region as
not cacheable.
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Steve is working in a database that holds patient data for a medical center. A patient's identification number serves as a primary key in the Patient table. A patient's identification number serves as a foreign key in the Doctor table. Steve wants to create a Form that displays Doctor table records with foreign key values that match the primary key value in the Patient table. How should Steve
proceed? A) Use the Form tool to create the form and Access will analyze the table relationships Steve created in the database, and automatically add a Split form to his form. B) Use the Form tool to create the form and Access will analyze the table relationships Steve created in the database, and automatically add a subform to his form. C) Use the Form tool to create the form and Access will analyze the table relationships Steve created in the database, and automatically add a Multi-items form to his form. D) Steve can only create a form that displays one record source at a time.
When a(n) ____ occurs, the interpreter default behavior is to display an error message and force the immediate termination of the program.
A. syntax B. error C. exception D. runtime
What IEEE standard defines the Link Aggregation Control Protocol (LACP)?
A) 802.1X B) 802.1af C) 802.3at D) 802.3ad
A(n) ____________________ is a link in a file, such as a workbook, to information within that file or another file.
Fill in the blank(s) with the appropriate word(s).