37.7.18 USB Test Mode Register
| Symbol | Description | Symbol | Description | Symbol | Description |
|---|---|---|---|---|---|
| R | Readable bit | HC | Cleared by Hardware | (Grey cell) | Unimplemented |
| W | Writable bit | HS | Set by Hardware | X | Bit is unknown at Reset |
| K | Write to clear | S | Software settable bit | — | — |
| Name: | TESTMODE |
| Offset: | 0x100F |
| Reset: | 0x0000 |
| Property: | PAC Write-Protection |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| FORCEHOST | FIFOACCESS | FORCEFS | FORCEHS | TESTPACKET | TESTK | TESTJ | TESTSE0NAK | ||
| Access | R/W | R/W/HC | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Bit 7 – FORCEHOST Test Mode Force Host Select bit
| Value | Description |
|---|---|
| 0 | Normal operation |
| 1 | Forces USB module into Host mode, regardless of whether it is connected to any peripheral |
Bit 6 – FIFOACCESS Test Mode Endpoint 0 FIFO Transfer Force bit
| Value | Description |
|---|---|
| 0 | No transfer |
| 1 | Transfers the packet in the Endpoint 0 TX FIFO to the Endpoint 0 RX FIFO |
Bit 5 – FORCEFS Test Mode Force Full-Speed Mode Select bit
This bit is only active if FORCEHST = 1.
| Value | Description |
|---|---|
| 0 | If FORCEHS = 0, places USB module into Low-Speed mode. |
| 1 | Forces USB module into Full-Speed mode. Undefined behavior if FORCEHS = 1. |
Bit 4 – FORCEHS Test Mode Force Hi-Speed Mode Select bit
This bit is only active if FORCEHST = 1.
| Value | Description |
|---|---|
| 0 | If FORCEFS = 0, places USB module into Low-Speed mode. |
| 1 | Forces USB module into Hi-Speed mode. Undefined behavior if FORCEFS = 1. |
Bit 3 – TESTPACKET Test_Packet Test Mode Select bit
This bit is only active if module is in Hi-Speed mode.
| Value | Description |
|---|---|
| 0 | Normal operation |
| 1 | The USB module repetitively transmits on the bus a 53-byte test packet. Test packet must be loaded into the Endpoint 0 FIFO before the test mode is entered. |
Bit 2 – TESTK Test_K Test Mode Select bit
This bit is only active if the USB module is in Hi-Speed mode.
| Value | Description |
|---|---|
| 0 | Normal operation |
| 1 | Enters Test_K test mode. The USB module transmits a continuous K on the bus. |
Bit 1 – TESTJ Test_J Test Mode Select bit
| Value | Description |
|---|---|
| 0 | Normal operation |
| 1 | Enters Test_J test mode. The USB module transmits a continuous J on the bus. |
Bit 0 – TESTSE0NAK Test_SE0_NAK Test Mode Select bit
This mode is only active if module is in Hi-Speed mode
| Value | Description |
|---|---|
| 0 | Normal operation |
| 1 | Enter Test_SE0_NAK test mode. The USB module remains in Hi-Speed mode but responds to any valid IN token with a NAK |