VTU eNotes On Modern Control Theory (Electrical And Electronics Engineering)
About this eBook
MOV A, R0 moves the content of memory pointed to by Ro into A MOV A, R1 moves the content of Register R1 to Accumulator A MOV 20h,30h moves the content of memory location 30h to 20h MOV A, 45h moves 45h to Accumulator A
b.MOV dest-bit , src-bit Function Move bit data Description MOV dest-bit , src-bit copies the Boolean variable indicated by the second operand into the location specified by the first operand. One of the operands must be the carry flag the other may be any directly addressable bit. No other register or flag is affected. Example MOV P1.3,C moves the carry bit to 3rd bit of port1 Veena Hegde, BMSCE ,Bangalore
Microcontroller C. MOV DPTR, data16 Function Load Data Pointer with a 16-bit constant Description MOV DPTR, data16 loads the Data Pointer with the 16-bit constant indicated. The 16-bit constant is loaded into the second and third bytes of the instruction. The second byte DPH is the high-order byte, while the third byte DPL holds the lower-order byte. No flags are affected. This is the only instruction which moves 16 bits of data at once. Example The instruction, MOV DPTR, 4567H loads the value 4567H into the Data Pointer. DPH holds 45H, and DPL holds 67H. d. MOVC A, A base-reg Function Move Code byte Description The MOVC instructions load the Accumulator with a code byte or constant from program memory. The address of the byte fetched is the sum of the original unsigned 8-bit Accumulator contents and the contents of a 16-bit base register, which may be either the Data Pointer or the PC. In the latter case, the PC is incremented to the address of the following instruction before being added with the Accumulator otherwise the base register is not altered. Sixteen-bit addition is performed so a carry-out from the low-order eight bits may propagate through higher-order bits. No flags are affected.
e. MOVC A, A PC
PC PC 1 A A PC f. MOVX dest-byte , src-byte Function Move External Description The MOVX instructions transfer data between the Accumulator and a byte of external data memory, which is why X is appended to MOV. There are two types of instructions, differing in whether they provide an 8-bit or 16-bit indirect address to the external data RAM. In the first type, the contents of R0 or R1 in the current register bank provide an 8-bit address multiplexed with data on P0. Eight bits are sufficient for external I O expansion decoding or for a relatively small RAM array. For somewhat larger arrays, any output port pins can be used to