lpcware

LPC177x/178x USB configuration clarification

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by jdupre on Mon Oct 28 17:31:17 MST 2013
On the LPC 177x/178x chips, is it possible to configure USB1 as a regular device (not OTG device) while simultaneously using USB2 as host?

User Manual 14.7.3  (Figure 51) shows host on USB1 and device on USB2.  There is no mention of the reversed configuration with device on USB1 and host on USB2.

Section 14.8.5 (Table 314) lists STCTRL PORT_FUNC bits:


Quote:
Controls connection of USB functions (see Figure 52). Bit 0 is set or cleared by hardware
when B_HNP_TRACK or A_HNP_TRACK is set and HNP succeeds. See Section 14.9.
00: U1 = device (OTG), U2 = host
01: U1 = host (OTG), U2 = host
10: Reserved
11: U1 = host, U2 = device
In a device-only configuration, the following values are allowed:
00: U1 = device. The USB device controller signals are mapped to the U1 port:
USB_CONNECT1, USB_UP_LED1, USB_D+1, USB_D-1.
11: U2 = device. The USB device controller signals are mapped to the U2 port:
USB_CONNECT2, USB_UP_LED2, USB_D+2, USB_D-2.




I'm not sure what is meant by "In a device-only configuration".  Does that mean no hosts?  Or does it only mean not operating in OTG mode? 

If I set STCTRL bits 1:0 to 00,  can I use USB1 as device (without the extra OTG hardware) while simultaneously using USB2 as host???


- Joe

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