DN=LOGIC_0, PHYEN=DISABLED, PUEN=DISABLED, PHYTST=MODE0, SSEL=LOW_SPEED, DP=LOGIC_0, DFREC=DIFF_0
Transceiver Control
| DN | D- Signal State. 0 (LOGIC_0): D- signal currently at logic 0. 1 (LOGIC_1): D- signal currently at logic 1. |
| DP | D+ Signal State. 0 (LOGIC_0): D+ signal currently at logic 0. 1 (LOGIC_1): D+ signal currently at logic 1. |
| DFREC | Differential Receiver State. 0 (DIFF_0): Differential 0 signalling is present on the bus. 1 (DIFF_1): Differential 1 signalling is present on the bus. |
| PHYTST | Physical Layer Test. 0 (MODE0): Mode 0: Normal (non-test mode) (D+ = X, D- = X). 1 (MODE1): Mode 1: Differential 1 Forced (D+ = 1, D- = 0). 2 (MODE2): Mode 2: Differential 0 Forced (D+ = 0, D- = 1). 3 (MODE3): Mode 3: Single-Ended 0 Forced (D+ = 0, D- = 0). |
| SSEL | USB Speed Select. 0 (LOW_SPEED): USB operates as a Low Speed device. If enabled, the internal pull-up resistor appears on the D- line. 1 (FULL_SPEED): USB operates as a Full Speed device. If enabled, the internal pull-up resistor appears on the D+ line. |
| PHYEN | Physical Layer Enable. 0 (DISABLED): Disable the USB physical layer Transceiver (suspend). 1 (ENABLED): Enable the USB physical layer Transceiver (normal). |
| PUEN | Internal Pull-up Resistor Enable. 0 (DISABLED): Disable the internal pull-up resistor (device effectively detached from the USB network). 1 (ENABLED): Enable the internal pull-up resistor when VBUS is present (device is attached to the USB network). |