Hi, I want to to copy the data of and external ROM adress to an external RAM adress,
my try :
CLR A
MOV DPTR, #8000H ; 8000H is the ROM Adress
MOVC A, @A+DPTR; A gets DPTR's data
MOV DPTR, #6000H ; 6000H is the RAM Adress
MOVX @DPTR, A

is this program correct? if yes is it the only method?

 

Hi, I want to to copy the data of and external ROM adress to an external RAM adress,
my try :
CLR A
MOV DPTR, #8000H ; 8000H is the ROM Adress
MOVC A, @A+DPTR; A gets DPTR's data
MOV DPTR, #6000H ; 6000H is the RAM Adress
MOVX @DPTR, A

is this program correct? if yes is it the only method?

I believe that is correct.
The MOVC instruction uses PSEN* as the "READ" signal for the external ROM. Data from the ROM is latched on the rising edge of PSEN*
The MOVX instruction uses WR* as the "WRITE" signal for the external RAM. The transaction is complete on the rising edge of WR*

In the datasheets the active low signals for read, write, and program store enable are indicated with an overbar, which can also be indicated with a trailing asterisk.

I am kind of curious about what kind of memory you have at address 0000H, in your particular system. For data memory it is the internal registers, RAM, and SFR space.

 

Why did you CLR A?

 

Why did you CLR A?

Because register A gets added to the DPTR before the indirect address fetch is executed. MOVC works that way, but MOVX does not.