Handset Software Evolution

Our last chapter provided some examples of the trade-offs implicit in software/hardware
partitioning when we discussed authentication and encryption. Implementing a function
in software provides lots of flexibility, but execution can be relatively slow. Implementing
a function in hardware means we lose flexibility, but the execution is much faster. Ahardware
implementation may also be more secure—less easy to compromise or attack without
leaving visible evidence. In hardware, an instruction might typically be expected to
execute in four clock cycles. In software, it can take 50 to 60 cycles—the cost of flexibility.
This chapter explores the evolution of software in the hardware versus software dilemma.