Questions regarding the examples of keyboard2mouse.

[inse1979]

When I run the keyboard2mouse example on the LPC55S69-EVK with the default settings, it works perfectly.

However, its current operation seems to be:

PC <--> LPCIP3511HS <--> LPC55S69 <--> OHCI <--> Keyboard

But I want to modify the operation mode to:
PC <--> LPCIP3511FS<-->LPC55s69<--> IP3516HS <--> Keyboard

So I tried the following modification:
usb_host_config.h:
#define USB_HOST_CONFIG_OHCI 0U
#define USB_HOST_CONFIG_IP3516HS 1U

usb_device_config.h
#define USB_DEVICE_CONFIG_LPCIP3511FS 1U
#define USB_DEVICE_CONFIG_LPCIP3511HS 0U

I encountered the following error message:

arm-none-eabi/bin/ld.exe: region `USB_RAM' overflowed by 3840 bytes

Memory region Used Size Region Size %age Used

PROGRAM_FLASH: 83524 B 630 KB 12.95%

SRAM: 29408 B 256 KB 11.22%

SRAMX: 0 GB 32 KB 0.00%

USB_RAM: 20224 B 16 KB 123.44%

SRAM4: 0 GB 16 KB 0.00%

How to solve this problem ?

[ZhangJennie]

Hi inse1979 

According to the error message "USB_RAM: 20224 B 16 KB 123.44%", your USB_RAM is overfolow. The reason is that, when you switch your USB Host controller from OHCI -> IP3516HS, the USB_RAM requirement exceeds 16k, which results in the overflow error.

IP3516HS driver needs more USB_RAM memory because its increased complexity.

While USB_RAM is only 16KB, your configuration is 20224B which is over the limit.

I ever tested the the same with SDK demos, switching USB demo from USB0. see article sections 2.1 and 2.2 of following article. There's no issue.

https://community.nxp.com/t5/LPC-Microcontrollers-Knowledge/LPC-ALL-Summary-of-Switching-USB-demo-fr...

Therefore, I suggest you optimize your code by disabling unnecessary USB classes or points to release more memory. Or reduce USB devices or endpoints or buffer sizes.

Hope this helps,

Jun Zhang