FAQs
English (US) 日本語 | Japanese 中文 | Chinese (Simplified)

5745b StandbyRAM

cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Show  only  | Search instead for 
Did you mean: 

5745b StandbyRAM

‎10-09-2018 09:38 PM
591 Views
wxh891222
Contributor I

Hi everyone,

We have two development boards,1.MPC5745B designed by ourself  2.DEVKIT-MPC5748G designed by nxp.

1.We use MPC5748G to test the Standby RAM for data retention after enter the standby mode. Because the Reference Manual indicates that Standby RAM is maintained after MCU enter into the standby mode and an external reset occured wake up the MCU. We modify the boot file startup.S to skip the initialization of the Standby RAM ECC during the process.

2.Now we switch to the MPC5745B board, the chip does not work properly during the read data (The phenomenon is that if you access the data in Standby RAM, the program will be stuck.) The phenomenon is not detected in MPC5748G(same code).

3.In the application note AN5114, there is no difference between MPC5745B and MPC5748G in the Standby RAM. We test many ways for this problem. The code can be used for MPC5748G. But when we use the MPC5745B, the code can not run well. We have tried make a new MPC5745B project, the result is same.

Can you help us solve this problem?  is there some related analysis or reference? Thanks.

Tags (1)
EReset181009.7z.zip
0 Kudos
Reply
1 Reply

‎02-26-2019 02:26 AM
403 Views
petervlna
NXP TechSupport
NXP TechSupport

Hello,

We use MPC5748G to test the Standby RAM for data retention after enter the standby mode. Because the Reference Manual indicates that Standby RAM is maintained after MCU enter into the standby mode and an external reset occured wake up the MCU. We modify the boot file startup.S to skip the initialization of the Standby RAM ECC during the process.

Yes, this is correct.

2.Now we switch to the MPC5745B board, the chip does not work properly during the read data (The phenomenon is that if you access the data in Standby RAM, the program will be stuck.) The phenomenon is not detected in MPC5748G(same code).

Is the data in Standby RAM valid? Do you see correct data after Standby Exit in Standby RAM when no code after exit is executed, just endless loop?

3.In the application note AN5114, there is no difference between MPC5745B and MPC5748G in the Standby RAM. We test many ways for this problem. The code can be used for MPC5748G. But when we use the MPC5745B, the code can not run well. We have tried make a new MPC5745B project, the result is same.

What does it means code cannot run well? Do you getting exception when you are accessing RAM or what?

regards,

Peter

0 Kudos
Reply