The USB peripheral has its own voltage regulator. When using the USB peripheral, a 5 V USB supply needs to be provided on the VBUS pin.
The USB peripheral has a dedicated internal voltage regulator for converting the VBUS supply to 3.3 V to be used by the USB signalling interface (D+ and D- lines, and pull-up on D+). The rest of the USB peripheral (USBD) is supplied through the main supply like other on-chip features. As a consequence, both VBUS and combinations of VDDH and VDD are required for USB peripheral operation. For details on configuring the main supplies, see Power supply modes and regulators.
When VBUS rises into its valid range, the software is notified through the USBDETECTED event. The USBREMOVED event is sent when VBUS goes below its valid range. Use these events to implement the USBD startup sequence described in USBD power-up sequence.
When VBUS rises into its valid range while the device is in System OFF, the device resets and transitions to System ON mode. The RESETREAS register will have the VBUS bit set to indicate the source of the wakeup.
See VBUS detection specifications for the voltage level where events are sent (VBUS,DETECT and VBUS,REMOVE) or where the system causes a wakeup from System OFF (VBUS,DETECT).
When the USBD peripheral is enabled through the ENABLE register and VBUS is detected, the regulator is turned on. A USBPWRRDY event is sent when the regulator's worst case settling time has elapsed, indicating to the software that it can enable the USB pull-up to signal a USB connection to the host.
The software can read the state of the VBUS detection and regulator output readiness at any time through the USBREGSTATUS register.
To ensure stability, the input and output of the USB regulator need to be decoupled with a suitable decoupling capacitor CVBUS. See Reference circuitry for the recommended values.
Base address | Domain | Peripheral | Instance | Secure mapping | DMA security | Description | Configuration | |
---|---|---|---|---|---|---|---|---|
0x50037000 |
APPLICATION | USBREG |
USBREGULATOR : S |
US |
NA |
USB regulator control |
Register | Offset | Security | Description | |
---|---|---|---|---|
EVENTS_USBDETECTED | 0x100 |
Voltage supply detected on VBUS |
||
EVENTS_USBREMOVED | 0x104 |
Voltage supply removed from VBUS |
||
EVENTS_USBPWRRDY | 0x108 |
USB 3.3 V supply ready |
||
PUBLISH_USBDETECTED | 0x180 |
Publish configuration for event USBDETECTED |
||
PUBLISH_USBREMOVED | 0x184 |
Publish configuration for event USBREMOVED |
||
PUBLISH_USBPWRRDY | 0x188 |
Publish configuration for event USBPWRRDY |
||
INTEN | 0x300 |
Enable or disable interrupt |
||
INTENSET | 0x304 |
Enable interrupt |
||
INTENCLR | 0x308 |
Disable interrupt |
||
USBREGSTATUS | 0x400 |
USB supply status |
Address offset: 0x100
Voltage supply detected on VBUS
Bit number | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ID |
A |
||||||||||||||||||||||||||||||||||
Reset 0x00000000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
A | RW |
EVENTS_USBDETECTED |
Voltage supply detected on VBUS |
||||||||||||||||||||||||||||||||
NotGenerated |
0 |
Event not generated |
|||||||||||||||||||||||||||||||||
Generated |
1 |
Event generated |
Address offset: 0x104
Voltage supply removed from VBUS
Bit number | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ID |
A |
||||||||||||||||||||||||||||||||||
Reset 0x00000000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
A | RW |
EVENTS_USBREMOVED |
Voltage supply removed from VBUS |
||||||||||||||||||||||||||||||||
NotGenerated |
0 |
Event not generated |
|||||||||||||||||||||||||||||||||
Generated |
1 |
Event generated |
Address offset: 0x108
USB 3.3 V supply ready
Bit number | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ID |
A |
||||||||||||||||||||||||||||||||||
Reset 0x00000000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
A | RW |
EVENTS_USBPWRRDY |
USB 3.3 V supply ready |
||||||||||||||||||||||||||||||||
NotGenerated |
0 |
Event not generated |
|||||||||||||||||||||||||||||||||
Generated |
1 |
Event generated |
Address offset: 0x180
Publish configuration for event USBDETECTED
Bit number | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ID | B | A | A | A | A | A | A | A | A | ||||||||||||||||||||||||||
Reset 0x00000000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
A | RW |
CHIDX |
[255..0] |
DPPI channel that event USBDETECTED will publish to. |
|||||||||||||||||||||||||||||||
B | RW |
EN |
|||||||||||||||||||||||||||||||||
Disabled |
0 |
Disable publishing |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Enable publishing |
Address offset: 0x184
Publish configuration for event USBREMOVED
Bit number | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ID | B | A | A | A | A | A | A | A | A | ||||||||||||||||||||||||||
Reset 0x00000000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
A | RW |
CHIDX |
[255..0] |
DPPI channel that event USBREMOVED will publish to. |
|||||||||||||||||||||||||||||||
B | RW |
EN |
|||||||||||||||||||||||||||||||||
Disabled |
0 |
Disable publishing |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Enable publishing |
Address offset: 0x188
Publish configuration for event USBPWRRDY
Bit number | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ID | B | A | A | A | A | A | A | A | A | ||||||||||||||||||||||||||
Reset 0x00000000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
A | RW |
CHIDX |
[255..0] |
DPPI channel that event USBPWRRDY will publish to. |
|||||||||||||||||||||||||||||||
B | RW |
EN |
|||||||||||||||||||||||||||||||||
Disabled |
0 |
Disable publishing |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Enable publishing |
Address offset: 0x300
Enable or disable interrupt
Bit number | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ID |
C |
B |
A |
||||||||||||||||||||||||||||||||
Reset 0x00000000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
A | RW |
USBDETECTED |
Enable or disable interrupt for event USBDETECTED |
||||||||||||||||||||||||||||||||
Disabled |
0 |
Disable |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Enable |
|||||||||||||||||||||||||||||||||
B | RW |
USBREMOVED |
Enable or disable interrupt for event USBREMOVED |
||||||||||||||||||||||||||||||||
Disabled |
0 |
Disable |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Enable |
|||||||||||||||||||||||||||||||||
C | RW |
USBPWRRDY |
Enable or disable interrupt for event USBPWRRDY |
||||||||||||||||||||||||||||||||
Disabled |
0 |
Disable |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Enable |
Address offset: 0x304
Enable interrupt
Bit number | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ID |
C |
B |
A |
||||||||||||||||||||||||||||||||
Reset 0x00000000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
A | RW |
USBDETECTED |
Write '1' to enable interrupt for event USBDETECTED |
||||||||||||||||||||||||||||||||
Set |
1 |
Enable |
|||||||||||||||||||||||||||||||||
Disabled |
0 |
Read: Disabled |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Read: Enabled |
|||||||||||||||||||||||||||||||||
B | RW |
USBREMOVED |
Write '1' to enable interrupt for event USBREMOVED |
||||||||||||||||||||||||||||||||
Set |
1 |
Enable |
|||||||||||||||||||||||||||||||||
Disabled |
0 |
Read: Disabled |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Read: Enabled |
|||||||||||||||||||||||||||||||||
C | RW |
USBPWRRDY |
Write '1' to enable interrupt for event USBPWRRDY |
||||||||||||||||||||||||||||||||
Set |
1 |
Enable |
|||||||||||||||||||||||||||||||||
Disabled |
0 |
Read: Disabled |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Read: Enabled |
Address offset: 0x308
Disable interrupt
Bit number | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ID |
C |
B |
A |
||||||||||||||||||||||||||||||||
Reset 0x00000000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
A | RW |
USBDETECTED |
Write '1' to disable interrupt for event USBDETECTED |
||||||||||||||||||||||||||||||||
Clear |
1 |
Disable |
|||||||||||||||||||||||||||||||||
Disabled |
0 |
Read: Disabled |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Read: Enabled |
|||||||||||||||||||||||||||||||||
B | RW |
USBREMOVED |
Write '1' to disable interrupt for event USBREMOVED |
||||||||||||||||||||||||||||||||
Clear |
1 |
Disable |
|||||||||||||||||||||||||||||||||
Disabled |
0 |
Read: Disabled |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Read: Enabled |
|||||||||||||||||||||||||||||||||
C | RW |
USBPWRRDY |
Write '1' to disable interrupt for event USBPWRRDY |
||||||||||||||||||||||||||||||||
Clear |
1 |
Disable |
|||||||||||||||||||||||||||||||||
Disabled |
0 |
Read: Disabled |
|||||||||||||||||||||||||||||||||
Enabled |
1 |
Read: Enabled |
Address offset: 0x400
USB supply status
Bit number | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ID |
B |
A |
|||||||||||||||||||||||||||||||||
Reset 0x00000000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
A | R |
VBUSDETECT |
VBUS input detection status (USBDETECTED and USBREMOVED events are derived from this information) |
||||||||||||||||||||||||||||||||
NoVbus |
0 |
VBUS voltage below valid threshold |
|||||||||||||||||||||||||||||||||
VbusPresent |
1 |
VBUS voltage above valid threshold |
|||||||||||||||||||||||||||||||||
B | R |
OUTPUTRDY |
USB supply output settling time elapsed |
||||||||||||||||||||||||||||||||
NotReady |
0 |
USBREG output settling time not elapsed |
|||||||||||||||||||||||||||||||||
Ready |
1 |
USBREG output settling time elapsed (same information as USBPWRRDY event) |
Symbol | Description | Min. | Typ. | Max. | Units | ||||
---|---|---|---|---|---|---|---|---|---|
VBUS |
Supply voltage on VBUS pin |
4.35 | 5 | 5.5 | V | ||||
VDPDM |
Voltage on D+ and D- lines |
VSS - 0.3 | VUSB33 + 0.3 | V |
Symbol | Description | Min. | Typ. | Max. | Units | ||||
---|---|---|---|---|---|---|---|---|---|
IUSB,QUIES |
USB regulator quiescent current drawn from VBUS (USBD enabled) |
170 | µA | ||||||
tUSBPWRRDY |
Time from USB enabled to USBPWRRDY event triggered, VBUS supply provided |
1 | ms | ||||||
VUSB33 |
On voltage at the USB regulator output (DECUSB pin) |
3.0 | 3.3 | 3.6 | V | ||||
RSOURCE,VBUS |
Maximum source resistance on VBUS, including cable, when VDDH is not connected to VBUS |
6 | Ω | ||||||
RSOURCE,VBUSVDDH |
Maximum source resistance on VBUS, including cable, when VDDH is connected to VBUS |
3.8 | Ω | ||||||
CDECUSB |
Decoupling capacitor on the DECUSB pin |
2.35 | 4.7 | 5.5 | µF |
Symbol | Description | Min. | Typ. | Max. | Units | ||||
---|---|---|---|---|---|---|---|---|---|
VBUS,DETECT |
Voltage at which rising VBUS gets reported by USBDETECTED |
3.4 | 4.0 | 4.3 | V | ||||
VBUS,REMOVE |
Voltage at which decreasing VBUS gets reported by USBREMOVED |
3.0 | 3.6 | 3.9 | V |