hello

I have question about SLD in example below:

L MW210// oreder num
L 12 // num of bytes per element
*D
SLD 3
L P#0.0 // it's pointer to 0th element (may have different value)
+D //pointer is ready to use
T MD40

why "SLD 3" ??

May someone explain me this ?

regards

mat84

the SLD 3-instruction converts the content of the accumulator (byte-offset) to the pointer-format. These 3 bits are reserved for the bit-offset.

Regards,

yy1

thank you for reply yy1

best regards

mat84

Hello mat84,

Actually the SLD 3 command does the same as
L 8
* D
The adress is multiplied with 8, because for indirect adressing not the Adress of the starting BYTE, but the Adress of the starting BIT is needed!

So if you want to access (read or write) e.g. DBx.DBW4
you have to calculate the starting adress of the pointer: 4*8=32
You want to read Word 4 = Bit32 (up to Bit 47) of the DB.

best regards..

thank you neo for excellent explanation and example

best regards

mat84

New question published by Damayanti is split to a separate thread with the subject How to use pointer to access bytes, bits, arrays from one DB and transfer it to another DB?.

Best regards
Min_Moderator