# # Paging

#

# Variables: # NBA: number of bits in the virtual address # NBO: number of bits for offset part of the virtual address # NBP: number of bits for VPN part of the virtual address # NP: number of pages # SA: size of the virtual address space (in bytes) # SP: size of a virtual page (in bytes) #

# Think about these relationships: # # From the number of bits in a virtual address, you can figure out # the number of bytes in the virtual address space, and vice versa: # NBA = log2(SA), or equally SA = 2^NBA # # From the number of pages in the virtual address space, you can figure # out the number of bits in the VPN part of a virtual address, and vice versa: # NBP = log2(NP), or equally NP = 2^NBP # # From the number of bytes in a page, you can figure out the number # of bits in the offset part of a virtual address, and vice versa: # NBO = log2(SP), or equally SP = 2^NBO # # The number of bits in the virtual address equals the number of # bits in the VPN part of the address plus the number of bits in # the offset part of the address. # NBO + NBP = NBA #

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#@ 11 If there are 1024 virtual pages, and 8 offset bits in a # virtual address, then what is the size of the virtual address space, # in bytes? # (enter an SA value)

#@ 12 If the virtual address space is 64 MB, and there are 12 # page bits in a virtual address, then what is the page size? # (enter an SP value)

#@ 13 If the virtual address space is 32 KB, and each page is 2 KB, # then how many virtual pages are there? # (enter an NP value)

#@ 14 If there are 2048 pages, and each page is 8 KB, then # how many bits in a virtual address? # (enter an NBA value)

#@ 15 If a virtual address has 32 bits, and the number of pages # is 1024*1024, then how many offset bits in a virtual address? # (enter an NBO value)