external SRAM interface with MPC555

[Sushmitha]

Hello,

 SRAM is required to be used with an MPC555, in an Avionics
application (-55C to 125C ambient temperature).

Program code will be downloaded from Flash memory(internal flash of
MPC555) to the SRAM. SRAM must be fast enough for the MPC555 to run
code at the full 40MHz speed?

 The minimum total amount of SRAM that is required is 256Kbytes, up
to 2Mbytes if possible. it can be x32 configuration or x16
configuration,

The usage of internal flash of the microcontroller and  external
SRAM interfaced to microcontroller MPC555 can be done?

Is it possible to interface SDRAM to MPC555.If yes how the control
signals will be interfaced?

Thanks,
Sushmitha

[Jean-Christophe MATHAE]

Sushmitha,
 
The most difficult thing will surely be to find a chip with the suitable temperature range...
 
 
 

Jean-Christophe MATHAE

CIRTEM
http://www.cirtem.com <http://www.cirtem.com/>

bâtiment Pointe Bleue
20, voie l'Occitane
BP661
31319 LABEGE cedex
France

Tél : [phone]

P Think Environment, print only if necessary


________________________________

De : MPC500@... [mailto:MPC500@...] De la part de Sushmitha
Envoyé : mardi 9 octobre 2007 08:15
À : MPC500@...
Objet : [MPC500] external SRAM interface with MPC555



Hello,

SRAM is required to be used with an MPC555, in an Avionics
application (-55C to 125C ambient temperature).

Program code will be downloaded from Flash memory(internal flash of
MPC555) to the SRAM. SRAM must be fast enough for the MPC555 to run
code at the full 40MHz speed?

The minimum total amount of SRAM that is required is 256Kbytes, up
to 2Mbytes if possible. it can be x32 configuration or x16
configuration,

The usage of internal flash of the microcontroller and external
SRAM interfaced to microcontroller MPC555 can be done?

Is it possible to interface SDRAM to MPC555.If yes how the control
signals will be interfaced?

Thanks,
Sushmitha



 


[Non-text portions of this message have been removed]

[Jean-Christophe MATHAE]

Sushmitha,


Interfacing a flow-through sync SRAM to the MPC555 is straitforward (glueless). Motorola/Freescale used to have an application note on this, but I cannot find it anymore.

But I told you in my last message, this kind of memory (flow-through sync sram) are difficult to find in extended temperature ranges...

Best regards.


Jean-Christophe MATHAE

CIRTEM
http://www.cirtem.com

bâtiment Pointe Bleue
20, voie l'Occitane
BP661
31319 LABEGE cedex
France

Tél : [phone]

[Dees Randy-rsaf30]

ISSI (http://www.issi.com) makes some SRAMs that are automotive
temperature grade.
 
See the MPC5xx evaluation board schematics (http://www.axman.com) how to
connect SRAM devices.
 
the internal flash on the MPC555 is optimized to give performance almost
as good as external fast SRAM.
 
SDRAMs usually require some interface logic. Most customers use SRAM or
external flash.

________________________________

From: MPC500@... [mailto:MPC500@...] On Behalf
Of Sushmitha
Sent: Tuesday, October 09, 2007 1:08 AM
To: MPC500@...
Subject: [MPC500] external SRAM interface with MPC555



Hello,

SRAM is required to be used with an MPC555, in an Avionics
application (-55C to 125C ambient temperature).

Program code will be downloaded from Flash memory(internal flash of
MPC555) to the SRAM. SRAM must be fast enough for the MPC555 to run
code at the full 40MHz speed?

The minimum total amount of SRAM that is required is 256Kbytes, up
to 2Mbytes if possible. it can be x32 configuration or x16
configuration,

The usage of internal flash of the microcontroller and external
SRAM interfaced to microcontroller MPC555 can be done?

Is it possible to interface SDRAM to MPC555.If yes how the control
signals will be interfaced?

Thanks,
Sushmitha


.
 
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sgId=3907/stime=1191910121/nc1=3848627/nc2=4507179/nc3=4025321>
 


[Non-text portions of this message have been removed]