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EXTERNAL MEMORY ON NXP LPC22XX DOES NOT WORK

Applies to: ARM Development Tools

Answer


Information in this article applies to:


QUESTION

I am using an Philips LPC2000 device and have a Phytec phyCORE LPC2294 target board. I am using the external RAM, but the external RAM seems not to work.

What can be wrong?

ANSWER

Working with external RAM requires that the chip selects are properly set. This is done in the STARTUP.S file if EXTERNAL_MODE is defined. See code below:

; Setup External Memory Pins
                IF      :DEF:EXTERNAL_MODE
                LDR     R0, =PINSEL2
                LDR     R1, =PINSEL2_Val
                STR     R1, [R0]
                ENDIF

To define EXTERNAL_MODE, add the following settings under Project — Options for Target:

Or in Options for File 'Startup.s':

MORE INFORMATION

SEE ALSO

Article last edited on: 2012-01-13 07:15:29

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