• State Resolved
  • Locked Locked
  • Replies 9 replies
  • Subscribers 77 subscribers
  • Views 6566 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

About Hardware Multiplier?

ferhat
Intellectual 380 points
Other Parts Discussed in Thread: MSP430FG4618

Hi, i'll use hardware multiplier, signed multiply and accumulate. I saved data in msp430fg4618 flash memory. I want to ask how can i read data from flash memory? I mean my data located at flash 0x7000 address. If i use OP2 = 0x7000, multiplier use 0x7000 value not my data's value. I want to use my data's value in OP2 not address value. How can i do that?

Thanks.

  • 0
    Genius 4530 points

    Hi Ferhat,

    Shouldnt you be using pointer to the flash address to read the value at the address and not the address itself?

    Something like (int*)(0x7000) should give you the value at the Flash address, if i am not wrong.

    Regards,

    Sid

  • 0 in reply to Sid
    Intellectual 380 points

    Hi sid, i tried that but there is a compiler error (IAR), it says ' Error[Pe513]: a value of type "int *" cannot be assigned to an entity of type "unsigned short"  '.

  • 0 in reply to ferhat
    Genius 4530 points

    Hi Ferhat,

    Have you tried replacing int* with (unsigned short*)? Since you are using a 16-bit microcontroller.

    Regards,

    Sid

  • 0 in reply to Sid
    Intellectual 380 points

    Yes, i tried that too but result is same, Error[Pe513]: a value of type "unsigned short *" cannot be assigned to an entity of type "unsigned short" .

  • 0 in reply to ferhat
    TI__Guru 63850 points

    OP2 is a register in the hardware multiplier that needs to be written with the value of the operand, not the address of the operand.  If your operand physically resides at address 0x7000, then the following should be used.

    unsigned short * operand2 = 0x7000 ;

    OP2 = *operand2 ;

  • 0 in reply to BrandonAzbell
    Intellectual 380 points

    I tried that but it gave similar error, Error[Pe144]: a value of type "int" cannot be used to initialize an entity of type "unsigned short *". So i tried this,

    unsigned int * operand2 = 0x7000;

    OP2 = *operand2;

    and compiler says, Error[Pe144]: a value of type "int" cannot be used to initialize an entity of type "unsigned int *".

    I tried int * operand2, compiler gave similar error again.

  • 0 in reply to ferhat
    TI__Guru 63850 points

    Sorry, my fault.  I was a little quick on the trigger.

    unsigned int * operand2 ;

     

    operand2 = (unsigned int *)0x7000 ;

    OP2 = *operand2 ;

  • 0 in reply to BrandonAzbell
    Genius 4530 points

    Hi Ferhat,

    Missed the * sign in my post.

    *(unsigned short *)(0x7000) or *(int *)(0x7000) should give you the value at corresponding flash address.

    Regards,

    Sid

  • 0 in reply to Sid
    Intellectual 380 points

    Thanks for help.

    Ferhat

**Attention** This is a public forum