How to declare a memory buffer with size 40000-byte in the program?

Sunglin Chen

Other Parts Discussed in Thread: MSP430F2619

Dear Friends,

I need to keep the ADC value more than 10000 sampling data, which will need a memory buffer size about 40000 bytes.
When I declared a buffer such as 'int32 pnBuf[10000];', CCS encountered a compiled error. I have also tried to use a dynamic declaration such as 'int32* pnBuf; pcBuf = new int32[10000];', but CCS doesn't support "new" declaration method.

Does anyone have ideas for this problem? Thank you.

Sunglin.

over 11 years ago

0 old_cow_yellow over 11 years ago

Guru 58965 points

I need 40000 dollars to pay my bill. I wrote a check, but it bounced. I went to my bank and try to withdraw in cash, they refused. What was the problem?

0 Kjell-Kristian Grane Torgersen over 11 years ago

Prodigy 140 points

Which mcu are you using? I haven't seen any msp430s with so much ram. But I haven't been looking for it either... new is a C++ keyword. Full C++ support is not common in the development tools for "small" microcontrollers. For dynamic memory allocation you could use malloc() instead of new.

0 Sunglin Chen over 11 years ago in reply to old_cow_yellow

Expert 2335 points

Hi OCW,

This is a very funny wise metaphor. I know the problem, but I would like to know a key to solve it. Thank you for your reply.

0 Sunglin Chen over 11 years ago in reply to Kjell-Kristian Grane Torgersen

Expert 2335 points

Hi Kjell-Krstian,

I use MSP430F2619, which has 120KB+256B Flash memory and 4K RAM. Does it mean that the maximum memory buffer that I could declare for total variables is 4K?

0 Ilmars over 11 years ago in reply to Sunglin Chen

Guru 46710 points

Sunglin Chen said:
Does it mean that the maximum memory buffer that I could declare for total variables is 4K?

Less. Because stack also needs some RAM

0 Ilmars over 11 years ago in reply to Sunglin Chen

Guru 46710 points

Sunglin Chen said:
This is a very funny wise metaphor. I know the problem, but I would like to know a key to solve it. Thank you for your reply.

As OCY needs more money in his bank account same way you need more RAM.

0 Sunglin Chen over 11 years ago in reply to Ilmars

Expert 2335 points

Hi Ilmars,

I know the answer now, and I will try to solve this problem myself. Thank you very much.

0 Ilmars over 11 years ago in reply to Sunglin Chen

Guru 46710 points

Why you need to keep so much records of ADC sampling data and why you want to use 32 bit integers if you have 12-bit ADC?

0 Kjell-Kristian Grane Torgersen over 11 years ago in reply to Sunglin Chen

Prodigy 140 points

Okay. I actually also use the msp430f2619.

Why do you need to keep track of 40000 adc samples ? Maybe you could modify your algorithm to use less memory while still giving good enough results ?

0 Sunglin Chen over 11 years ago in reply to Kjell-Kristian Grane Torgersen

Expert 2335 points

Hi Kjell,

Thank you for your suggestions. I'm trying to modify my digital processing method now. Thank you again.

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How to declare a memory buffer with size 40000-byte in the program?