Architecture
1609
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Universal Serial Bus 2.0 (USB) Controller
Table 34-1. USB Clock Multiplexing Options
CFGCHIP2.
USB0PHYCLKMUX
bit
CFGCHIP2.
USB1PHYCLKMUX
bit
USB2.0
Clock
Source
USB1.1
Clock
Source
Additional Conditions
0
0
USB_REFCLKIN
CLK48MHz output
from USB2.0 PHY
USB_REFCLKIN must be 12, 24, 48, 19.2,
38.4, 13, 26, 20, or 40 MHz. The PLL inside
the USB2.0 PHY can be configured to
accept any of these input clock frequencies.
0
1
USB_REFCLKIN
USB_REFCLKIN
USB_REFCLKIN must be 48 MHz. The PLL
inside the USB2.0 PHY can be configured to
accept this input clock frequency.
1
0
PLL0_AUXCLK
CLK48MHz output
from USB2.0 PHY
PLL0_AUXCLK must be 12, 24, 48, 19.2,
38.4, 13, 26, 20, or 40 MHz. The PLL inside
the USB2.0 PHY can be configured to
accept any of these input clock frequencies.
1
1
PLL0_AUXCLK
USB_REFCLKIN
PLL0_AUXCLK must be 12, 24, 48, 19.2,
38.4, 13, 26, 20, or 40 MHz. The PLL inside
the USB2.0 PHY can be configured to
accept any of these input clock frequencies.
USB_REFCLKIN must be 48 MHz.
Table 34-2. PHY PLL Clock Frequencies Supported
CFGCHIP2.USB0REF_FREQ bit
Frequency
1h
12.0 MHz
2h
24.0 MHz
3h
48.0 MHz
4h
19.2 MHz
5h
38.4 MHz
6h
13.0 MHz
7h
26.0 MHz
8h
20.0 MHz
9h
40.0 MHz