Accessing SDRAM on WildFire 5282 (Coldfire 5282)

[Dietrich]

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Mar 15, 2006, 3:17 AM

Post #1 of 2 (17 views)
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[ColdFire] Accessing SDRAM on WildFire 5282 (Coldfire 5282) Can't Post

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Hi there,

I'm currently programming the WildFire 5282 board, which uses the
ColdFire 5282 microcontroller. Programming environment is eclipse,
programming language is C (there is also a wildfire run time library
available). (Furthermore, I'm a newbie in programming microcontrollers...)

When allocating variables (e.g., an "int"), they seem to be stored
within the user stack (the board's Internal SRAM, size: 64 KB). But for
a programme, I'd like to store the variables in the board's SDRAM (16
MB). But I do not know, how to tell the programme to allocate variables
in SDRAM. Can anyone help me?

TIA,
Henry

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Mar 15, 2006, 7:04 AM

Post #2 of 2 (16 views)
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RE: [ColdFire] Accessing SDRAM on WildFire 5282 (Coldfire 5282) [In reply to] Can't Post

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Henry,

(non-static) Variables allocated within a function scope are allocated off
the stack. Statics and variables allocated at the module or global scope
are generally not allocated off the stack. Your solution may be as simple
as defining the variables outside the body of a function or declaring them
as static.

The memory space for static allocation is usually, I believe, determined by
a linker script. The exact format for the linker script can vary greatly
from one compiler/linker to the next. Perhaps you have some sample code,
build files, and memory maps for the WildFire board which you could examine?

John

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-----Original Message-----
From: Henry
Sent: Wednesday, March 15, 2006 6:18 AM
Subject: [ColdFire] Accessing SDRAM on WildFire 5282 (Coldfire 5282)


Hi there,

I'm currently programming the WildFire 5282 board, which uses the
ColdFire 5282 microcontroller. Programming environment is eclipse,
programming language is C (there is also a wildfire run time library
available). (Furthermore, I'm a newbie in programming microcontrollers...)

When allocating variables (e.g., an "int"), they seem to be stored
within the user stack (the board's Internal SRAM, size: 64 KB). But for
a programme, I'd like to store the variables in the board's SDRAM (16
MB). But I do not know, how to tell the programme to allocate variables
in SDRAM. Can anyone help me?

TIA,
Henry

Message Edited by Dietrich on 03-31-2006 03:37 PM

Message Edited by Dietrich on 04-01-2006 11:21 AM

Message Edited by Dietrich on 04-04-2006 09:20 PM