Describing embedded system’s processing behavior
Can be extremely difficult
Complexity increasing with increasing IC capacity
Past: washing machines, small games, etc.
Hundreds of lines of code
Today: TV set-top boxes, Cell phone, etc.
Hundreds of thousands of lines of code
Desired behavior often not fully understood in beginning
Many implementation bugs due to description mistakes/omissions
English (or other natural language) common starting point
Precise description difficult to impossible
Example: Motor Vehicle Code – thousands of pages long...