$.$ Explain the difference between the stack and the stack pointer $($SP$)$ by using an example.

$2.$ An $8051$ microcontroller is to execute programs from an external ROM. Specify the control

signals and their logic values for enabling external ROM access. Also specify the register $($and

its initial value after reset$)$ that will identify the first instruction to be fetched.

$33$

$3.$ The $8051$ is said to have $128$ bytes of internal data memory. However, referring to the

memory map, the on$-$chip data memory of the $8051$ is from $00$H to $0$FFH$,$ giving $256$

locations. Why is this so$?$

$4.$ Illustrate how two $32$k$-$byte static RAMs could be interfaced to the $8051$ so that they occupy

the full $64$k external data space.

$5.$ What is the difference between the $8051$s idle mode and power down mode?

$6.$ Illustrate how $16$k$-$byte x$8$ ROM memories could be connected $($expanded$)$ so that they form

an overall $32$k$-$byte x $16$ ROM memory.

$7.$ Illustrate how $8$k$-$byte x$8$ RAM memories could be connected $($expanded$)$ so that they form

an overall $32$k$-$byte x $8$ RAM memory.

$8.$ Illustrate how $32$k$-$byte x$8$ ROM memories could be connected $($expanded$)$ so that they form

an overall $32$k$-$byte x $32$ ROM memory