Embedded Design Lifecycle 7 Phases Specify Product Maintain

Embedded Design Lifecycle

7 Phases Specify Product Maintain & Upgrade Partition Hardware/Software No Done? Yes Software Design Hardware Design Integrate Test & Release 2

Focus in this course n n n Software Design Software/Hardware integration at the application level High-level programming language n n No VHDL, bit manipulation We use the light sensor, but we don’t focus on how to build one 3

It’s Alive!!…or IS IT? n n n Design Correct Hardware the first time through n No dead wires, problems Design perfect, bug-free software the first time Throw it all together, and it works! 4

Why Not? n n n Complex behavior only analyzable as it occurs Accurate simulations aren’t USUALLY worth the effort Modeling tools continue to improve 5

Before we get into Software… n n Selecting a microprocessor The JSTamp, RCX, NXT n n n http: //graphics. stanford. edu/~kekoa/rcx/#Ov erview http: //jstamp. systronix. com/Resource/jstamp _datasheet. pdf Enter Lego NXT n Industrial-strength ARM processor 6

Selecting a Microprocessor n n Embedded Systems usually task-specific Designs can be highly optimized You want “the right” CPU for the job Final selection must pass 5 critical tests 7

Five Tests 1. 2. 3. 4. 5. Available in a suitable implementation Capable of sufficient performance Supported by a suitable OS Supported by adequate tools Non-technical issues 8

Suitable Implementation n Cost n n n Off-the-shelf-parts highly integrated High Performance n n Specialized gates Specialized circuits 9

“Sufficient” Performance n n n Difficult to quantify as things get more complex Has less to do with computational power More to do with n n Hardware architecture vs. the more demanding tasks 10

Suitable RTOS n n You might prefer one OS over another Porting is not an easy task Hardware issues Software issues 11

Adequate Tools n n n Critical to success Often task-specific toolset Minimum Needs n n n Good cross-compiler Good debugging support Often have n n Host-based tools, IDEs Specialized tools such as an ICE 12

Other Issues n n Prior commitment to a processor family Prior restrictions on languages Prior experience of team members Time-to-market factors 13