[Question] How about "ohci_data" located in iRAM for nxpUSBlib V0.98b

lpcware — Wed, 15 Jun 2016 16:53:37 GMT

Content originally posted in LPCWare by ruanlin on Sun Feb 17 04:52:23 MST 2013
Now I'm porting nxpUSBlib V0.98b, and progressing build step via batch build,KEIL 4, with config as:
BSP=MCB1700
CDL=LPC17xx
Example_MassStorageHost=MCB1700
LPCUSBLib=LOC17xx_Host
Select Device for Target=LPC1768

My question is about the RAM location "ohci_data" in IRAM.
OHCI_HOST_DATA_Type ohci_data[MAX_USB_CORE] __DATA(USBRAM_SECTION);
Regarding dummy macro defined for "__DATA(x)", "ohci_data" should be located in IRAM1 as common .bss and corresponding text can be found in map file as below.
ohci_data 0x10001100 Data 1280 ohci.o(.bss)

I ask so because i saw "ohci_data" located in iRAM2(start_add 0x2007C000, size 0x8000)in other sample code.
I wounder whether or not it's correct that the "ohci_data" mapped int IRAM1? If not correct,is the problem caused by incorrect configuration for the KEIL proj? How about the correct one?
Regarding various Macro definition for "__DATA(USBRAM_SECTION)", is there any rules or priciples to locate "ohci_data" in IRAM area? Could some one please kindly to give brief specification?

Thanks very much!

Re: [Question] How about "ohci_data" located in iRAM for nxpUSBlib V0.98b

lpcware — Wed, 15 Jun 2016 16:53:38 GMT

Content originally posted in LPCWare by Tsuneo on Sun Feb 17 09:19:08 MST 2013
On LPC17xx, you may place the USB-DMA area either on the main SRAM or on a separate SRAM (bank0/bank1). When USB-DMA area lives in one of SRAM bank, separately from other variables/stack/heap, you'll get better performance, thanking to multilayer AHB matrix.

Tsuneo

LPC MicrocontrollersのトピックRe: [Question] How about "ohci_data" located in iRAM for nxpUSBlib V0.98b

[Question] How about "ohci_data" located in iRAM for nxpUSBlib V0.98b

Re: [Question] How about "ohci_data" located in iRAM for nxpUSBlib V0.98b