Number of bits in TLB tag

Question

A CPU generates 32 bit virtual address. The page size is 2KB. The translation look aside buffer (TLB) can hold 256 page table entries and is 2 way set associative mapping. The number of bits in TLB tag is ____ and total bits in single TLB entry ____? 

Ans for TLB tag:  14 bits ( not sure)  for first part

SOL acc to me:  11 bits are offset , table address index will be 7 bits and therefore tag will be 32 - 11 - 7 = 14

Comments

for first part 14

for second part 21

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how 2nd part is 21?

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check

Answer 1

Block Size=2KB=2^11B

#f bits required for Word/Block Offset=11 bits

#Line(N)=256

Total No of Sets=N/P-Way=256/2=128=2^7

#f Bits required for Set Offset=7bits

#f bits required for Tag=32-(11+7)=14bits

                                                          <----------------------32--------------------->

Tag	Set Offset	Block Offset
14	7	11

No of Entry in TLB=LAS/Page Size

                              = 2^32/2^11=(2^21)B

#f bits required for tlb entry=21

 

Comments

Shouldn't the tlb contain frame number? Here, the physical address space is not given, so how can only the virtual page numbers be the answer for the 2nd part?