types of processor Flashcards
stored program concept
Program must be loaded into main mem to be executed
Instructions fetcehd 1 at time, decoded, executed dequentially by cpu
Sequqnce of instruc only changed by conditional or unconditional jump instruc
von neumann arch
instruc + data stored in same main mem
transferred using single shared bus
harvard arch
data and instruc in different memories , use different buses
what is harvard ach commonly used in
embedded systems
digital signal processing (DSP)
pros of harvard arch
no bottlenecking
diffferent size mem + word length can be used for data and instruc
advantage von neumann arch
cheaper
less complex
simpler design of CU
data from mem and devices accessed same way
whats von neumann arch used in
pcs, laptops, servers
what do data and instruc share in v.Neu arch
same mem + same word length
why is 1 bus a con for v.Neu
and why is it a pro
bottlenecking can occur
but simpler for cu design
pro and con of 2 buses harvard arch
pro - allow parallel access to data and instruc
con - more complicated and expensive for cu design
contemporary arch
aspects of both Neu + harv arch
e.g in desktop comp - 1 main mem for data and instruc, but cache divided into data and instruc cache
special feature of some dsps
multiple parallel data buses + only 1 instruc bus
CISC
large instruc set - used to do tasks in as few lines of assembly lang as possible
RISC
small num of simple instruc (each taking 1 clock cycle) which are used to do all operations in many registers
avantage CISC
quciker to code program
compiler has little work to do to translate high lvl lang to machine code
little ram used to STO instructions
