MK64FX512VLQ12 : Does it have 256KB of SRAM or 192KB of SRAM

[alexpimenov]

In the data sheet it says that SRAM size is 256KB , but in the reference manual  section 3.5.3.1   SRAM is 192KB for MK64FX512VLQ12 CPU.

Which information is correct?

Data Sheet:

http://www.nxp.com/assets/documents/data/en/data-sheets/K64P144M120SF5.pdf 

Reference Manual:

http://www.nxp.com/assets/documents/data/en/reference-manuals/K64P144M120SF5RM.pdf 

[alexpimenov]

Thanks for you help .

[Hui_Ma · Accepted solution]

Hi,

MK64FX512VLQ12 has 256KB SRAM, the datasheet list the correct SRAM memory size.

I will forward Kinetis product team about K64 reference manual table 2-11 with incorrect SRAM size of MK64FX512VLQ12.

Sorry for that may bring any inconvenience to you.

Have a great day,
Ma Hui

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[alexpimenov]

It looks like it has 256KB of SRAM. I've just tried your suggestion and it worked. I was able to access 0x2002000 - 0x20030000  address range, with no hard faults.

I guess there is an error in the reference manual .

The  linker script file that comes with latest SDK2.2 (generated with SDK builder)for this CPU also limits RAM size to 192KB.  

MEMORY
{
m_interrupts (RX) : ORIGIN = 0x00000000, LENGTH = 0x00000400
m_flash_config (RX) : ORIGIN = 0x00000400, LENGTH = 0x00000010
m_text (RX) : ORIGIN = 0x00000410, LENGTH = 0x0007FBF0
m_data (RW) : ORIGIN = 0x1FFF0000, LENGTH = 0x00010000
m_data_2 (RW) : ORIGIN = 0x20000000, LENGTH = 0x00020000
}

Is linker script  also incorrect? I'm wondering if it's save to increase m_data_2 memory area, to get all 256KB?  

[mjbcswitzerland]

Alex

This is quite a strange situation - I haven't heard of such a 'serious' error in a user manual before, nor that the reference code follows the error. Nor that the user's manual is still inaccurate after more that 3 years, even after it was reported in the other post in its very latest revision 6 months ago....

Possibly the FX512 parts are rarely used (?) although they are popular for the Teensy 3.5

If you physically have 256k of SRAM you can of course change the length of m_data_2 to 0x00030000

Regards

Mark

http://www.utasker.com/kinetis/FRDM-K64F.html
http://www.utasker.com/kinetis/TWR-K64F120M.html
http://www.utasker.com/kinetis/TEENSY_3.5.html

[mjbcswitzerland]

Hi Alex

Very good question!

One of the two is obviously wrong, but I don't know which.

if you have the chip in question see whether you can access SRAM at 0x20020000. If it hard faults it has 192k, if it doesn't it has 256k.

Regards

Mark