Explain the 16-bit registers DPTR and SP of 8051.
DPTR:
DPTR stands for data pointer. DPTR having of a high byte (DPH) and a low byte (DPL). Its function is to hold a 16-bit address. It might be manipulated as a 16-bit data register or as two independent 8-bit registers. It serves as a base register in indirect jumps, lookup table instructions and external data transfer.
SP:
SP stands for stack pointer. SP is an 8- bit wide register. It is enhanced before data is stored during PUSH and CALL instructions. The stack array can reside anywhere in on-chip RAM. The stack pointer is initialised to 07H after a reset. This causes the stack to start at location 08H.