•There are basically 5 ways of specifying
source/destination operand addresses:
•1. Particular On-chip Resources:
includes the Accumulator (A), the Stack Pointer (SP), the Data Pointer (DP), the Program Counter (PC), and the Carry (C). Other
On-chip Registers are Memory-mapped while these
have special Op-codes.
•2. Immediate operands:
sign is the designator. These are 8-bits except for DPTR contents
•3. Register operands:
as Rn, where n is 0..7. One of the four Register Banks is used (selected by RS0 and RS1 in PSW).
•4. Direct Operands:
00 to FF Hex, specifies one of the internal data addresses.
•5. Indirect Address:
as @Ri, where i is 0 or 1, uses the contents of R0 or R1 in the selected Register Bank to specify the address. Other
form is @A, using Accumulator contents.