$(5$pts$)$Fill in the blanks

a$.$ In $8051,$ the internal data memory space is divided between and $(80$H$-0$FFH$).$

$(00H-7FH)$

b$.$ is used to define a constant without occupying a memory location.

c$.$ In general, flag is used to detect errors in unsigned arithmetic operations. only used to detect errors in signed arithmetic operanions. flag is

d$.$ is used to define data, the numbers can be in decimal, binary, hex, or ASCII formats.

e$.$ points to the address of the next instruction to be executed.