USB on-the-go full-speed/high-speed (OTG_FS/OTG_HS) RM0390
1144/1328 RM0390 Rev 4
31.15.17 Host-mode registers
Bit values in the register descriptions are expressed in binary unless otherwise specified.
Host-mode registers affect the operation of the core in the host mode. Host mode registers
must not be accessed in device mode, as the results are undefined. Host mode registers
can be categorized as follows:
31.15.18 OTG host configuration register (OTG_HCFG)
Address offset: 0x400
Reset value: 0x0000 0000
This register configures the core after power-on. Do not make changes to this register after
initializing the host.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
Res. Res. Res. Res. Res. Res. Res. Res. Res. Res. Res. Res. Res. Res. Res.
1514131211109876543210
Res. Res. Res. Res. Res. Res. Res. Res. Res. Res. Res. Res. Res. FSLSS FSLSPCS[1:0]
rrwrw
Bits 31:3 Reserved, must be kept at reset value.
Bit 2 FSLSS: FS- and LS-only support
The application uses this bit to control the core’s enumeration speed. Using this bit, the
application can make the core enumerate as an FS host, even if the connected device
supports HS traffic. Do not make changes to this field after initial programming.
1: FS/LS-only, even if the connected device can support HS (read-only).
Bits 1:0 FSLSPCS[1:0]: FS/LS PHY clock select
When the core is in FS host mode
01: PHY clock is running at 48 MHz
Others: Reserved
When the core is in LS host mode
00: Reserved
01: Select 48 MHz PHY clock frequency
10: Select 6 MHz PHY clock frequency
11: Reserved
Note: The FSLSPCS must be set on a connection event according to the speed of the
connected device (after changing this bit, a software reset must be performed).