DR805X Datasheet, PDF (55/79 Pages) Digital Core Design – 8-bit RISC Microcontroller Instructions set details ver 3.10

DR805x Instructions set details
3.26. MOVX
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Instruction: MOVX <dest-byte>, <src-byte>
Function: Move external
Description:
The MOVX instructions transfer data between the accumulator and a
byte of external data memory, hence the X appended to MOV. There
are two types of instructions, differing in whether they provide an eight-
bit or sixteen-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 eight-bit address, in the second type of MOVX instructions,
the data pointer generates a sixteen-bit address. Please refer to the
section “External Data Memory” of core specification for more
information.
3.26.1.
MOVX A, @RI
Operation: (PC) ← (PC) + 1
(A) ← ((Ri))
Bytes:
1
Cycles:
3
Encoding:
1110001 i
3.26.2.
MOVX A, @DPTR
Operation: (PC) ← (PC) + 1
(A) ← ((DPTR))
Bytes:
1
Cycles:
2
Encoding:
11100000
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