Hello,
I'm using an LPC1788 with a MT48LC16M16 SDRAM chip. All works well and I do not have any issues with the external memory in normal operation.
I use a bootloader to configure the external memory and run a memory check. My problem is when I get a watchdog reset in the main application (I'm causing them on purpose for testing) the configuration of the external SDRAM runs in the bootloader and one of two things happens:
1) Everything works exactly the same as on a power up (50% of the time)
2) As soon as I try and access the memory I get a fault that kills my debugger. (The other 50% of the time)
Does anyone have any idea what is going on? Note I have tried this with SCB bit 1 on/off no difference. I've also tried not re-configuring the EMC when it's a watchdog reset but this seems to fail every time.
Does anyone know how to safely and surely reset this SDRAM?
Thanks
M
but this seems to fail every time
The configuration itself or startup?
Thanks for the replies.
@JB JB losing all the SDRAM data is not a problem (This is expected when a watchdog reset occurs for my design).
@Tamir - By fail every time I mean the SDRAM configuration/initialization. In other words the bootloader runs fine, it configures the SDRAM but at the first point of access of the external ram it hard faults.
I also have some external NOR and because this device has a reset line I never get any issues. With the SDRAM it's like I'm not forcing it to reset properly.