LPC54608 RAM

[実奥山]

LPC54608 have 192K RAM for general use.

LPC54608 have 8K RAM for USB use.

I'd like to increase RAM.

Can I use 8K RAM for general use?

[soledad]

Hi, 

The  8 KB SRAM is available for USB operations or it can be used as a general purpose SRAM when not used for USB.

Have a great day,
Sol

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[belmontbob59]

8K dedicated USB RAM is only actively being used in USB1 for DMA access. If you are not using USB1 device block then I believe you can use  USB RAM for other purposes. Please note it is not contiguous to SRAM0/1/2/X  

[sandeepvl]

Bob,

Does that mean when USB1 (HS) is powered, USB RAM cannot be used by USB0 (FS)?

I have an use case where USB1 (HS) has to act as USB device and has to be connected to PC, and at the same time, USB0 (FS) has to be used as USB host to connect USB sticks.

Will this work?

Regards

Sandeep

[belmontbob59]

Yes this will work. As a proof of concept look at SDK keyboard2mouse example; it allocates host (USB0) and device (USB1) controllers  data along with OSA variables in USB dedicated RAM.

Load Region LR_m_usb_ram (Base: 0x40100000, Size: 0x00000000, Max: 0x00002000, ABSOLUTE)

Execution Region ER_m_usb_ram (Base: 0x40100000, Size: 0x00001d60, Max: 0x00002000, ABSOLUTE, UNINIT)

Base Addr Size Type Attr Idx E Section Name Object

0x40100000 0x000000d0 Zero RW 1614 m_usb_global usb_osa_bm.o
0x401000d0 0x00000030 PAD
0x40100100 0x00000028 Zero RW 2103 m_usb_global usb_device_hid.o
0x40100128 0x00000018 PAD
0x40100140 0x00000080 Zero RW 2186 m_usb_global usb_device_class.o
0x401001c0 0x00000040 PAD
0x40100200 0x00001560 Zero RW 2275 m_usb_global usb_device_lpcip3511.o
0x40101760 0x00000070 Zero RW 2497 m_usb_global usb_device_dci.o
0x401017d0 0x00000030 PAD
0x40101800 0x00000560 Zero RW 3327 m_usb_global usb_host_ohci.o