Chapter 9.6, Problem 9.4PP

A.

Program Plan Intro

Virtual address:

Virtual page number (VPN) and virtual page offset (VPO) are the two components of virtual address. Virtual address is “14 bits” format.

B.

Program Plan Intro

The page size (P) is 64bytes; using the page size find the number of bits in VPN.

The formula for page size as follows:

$P=2^p$

Substitute “P = 64” in the above formula

$\begin{array}{l}P=2^p\\ 64=2^p\\ 2^6=2^p\\ \boxed{p=6}\end{array}$

Therefore, the “p” value represents virtual page offset (VPO) and physical page offset (PPO).

Number of bits in VPN is calculated as follows:

n = 14

p = 6

$\begin{array}{c}NumberofbitsinVPN=n-p\\ =14-6\\ =8\end{array}$

The VPN has additional two more components. They are TLB tag (TLBT) and TLB index (TLBI). The TLB is “4 ways” associative with “16” entries totally. Using the TLB find the value of TLBI and TLBT.

The formula for TLB as follows:

$T=2^t$

Substitute “T = 4” in the above formula

$\begin{array}{l}T=2^t\\ 4=2^t\\ 2^2=2^t\\ \boxed{t=2}\end{array}$

Therefore, the “t” value represents TLBI.

TLBI and TLBT are calculated as follows:

The “t” value represents TLBI. Therefore, the value of TLBI is “2”.

TLBI = 2

VPN = 8

$\begin{array}{c}TLBT=VPN-TLBI\\ =8-2\\ =6\end{array}$

Therefore, the value of TLBT is “6”.

C.

Program Plan Intro

Physical address:

Physical page number (PPN) and physical page offset (PPO) are the two components of physical address. Physical address is “12 bits” format. The physical page offset (PPO) is identical to the virtual page offset (VPO).

D.

Program Plan Intro

The physical address has additional three more components. They are Byte offset within cache block (CO), Cache index (CI) and Cache tag (CT).