LPC MicrocontrollersのトピックRe: local SRAM vs AHB SRAM

local SRAM vs AHB SRAM

lpcware — Wed, 15 Jun 2016 18:23:33 GMT

Content originally posted in LPCWare by Dill on Tue Oct 07 23:54:42 MST 2014
I can't find any information about how to deal with AHB SRAM. Can it be used like local SRAM or are there differences?

I just ran into a problem with AHB SRAM and IAP:

there are four 16k blocks of AHB SRAM.
When the 512 bytes I want to copy to flash are located fully in one block, it works:

// ---- OK, this is completely in the third of four blocks
flash_storage           0x2000be00   0x200  Data  Lc  IAP.o [1] 

// ---- NOT OK, this is in the third and fourth block
flash_storage           0x2000be04   0x200  Data  Lc  IAP.o [1]

So obviously there are some pitfalls using AHB SRAM.

Re: local SRAM vs AHB SRAM

lpcware — Wed, 15 Jun 2016 18:23:34 GMT

Content originally posted in LPCWare by cfb on Thu Oct 09 01:50:42 MST 2014
Check the value in the ETB SRAM configuration register (ETBCFG, address 0x4004 3128).

When Bit0 = 0 ETB accesses SRAM at address 0x2000 C000.
When Bit0 = 1 AHB accesses SRAM at address 0x2000 C000.

"When the ETB is used, the 16 kB memory space at 0x2000 C000 must not be used by any other process."

The reset value of Bit0 is supposed to be 1, so if it isn't you will need to find out what has changed it.

Re: local SRAM vs AHB SRAM

lpcware — Wed, 15 Jun 2016 18:23:35 GMT

Content originally posted in LPCWare by Dill on Tue Oct 28 04:56:09 MST 2014

thats it, thanks!