How to use Overlay RAM?

hongpingxu-b364 — Mon, 25 Jan 2016 07:47:20 GMT

Hi,

Can anyone share use the reference code about how to use Qorivva 57XX Overlay RAM? If the target MCU is Rainer is best.

Best regards,

Re: How to use Overlay RAM?

lukaszadrapa — Wed, 27 Jan 2016 11:35:18 GMT

Hi,

you need to configure the relevant registers to remap a flash location to internal overlay RAM:

PFLASH_PFCRDn_Word1

PFLASH_PFCRDn_Word2

PFLASH_PFCRDn_Word3

User need to refer the Flash Mirrored location (for example 0x08F9_C000) as the Logical StartAddress not the actual Flash address. Overlay RAM location should be used as the Physical StartAddress (for example internal Overlay RAM 0x0D00_0000 – I’m talking about MPC5746R, it can be different on other devices). Please refer the Memory Map excel to find out which areas can be overlayed.

Then enable the remapping by Platform Flash Remap Descriptor Enable Register and by Platform Flash Remap Control Register.

Initial data should be copied from flash to overlay SRAM by user. Once the calibration is done, the data should be programmed back to flash by user - this is not done automatically, of course.

Overlay SRAM is normally used for system development purposes only.

Regards,

Lukas

MPC5xxx中的主题 How to use Overlay RAM?

How to use Overlay RAM?

Re: How to use Overlay RAM?