Problem $1.($a$)$ Theretfieinstruction restores the context $($by restoring the SR register$)$ and reen$-$ ables interrupts $($by restoring IPL$).($b$)$ The Timer$1$ interrupt vector has a lower address and hence a higher natural priority so it is serviced first. $($c$)$ No$.$ If there are four received data words are in the buffer and a stop bit for a fifth data word in the UxRSR register is detected, the OERR bit is set. If the OERR bit is set any new received data is ignored and does not overwrite the contents of the buffer or the UxRSR register. You must empty the contents of the buffer before resetting the OERR bit. So nothing is overwritten but arriving data might be ignored. $($d$)$ We have a read command $(1$ byte$),$ an address $(1$ byte$),$ and then $512$ bytes of data. Using a sequential read this would take about $(1+1+512)10-6=514$s $($e$)$ Resolution is $3\mathrm{.}3$ V$/212=0\mathrm{.}805664$ V$.$