Pad Calibration
The Pad Calibration values must be loaded from the NVM Software Calibration Area into the USB Pad Calibration register by software, before enabling the USB, to achieve the specified accuracy.

Refer to NVM Software Calibration Area Mapping for further details.

Refer to for further details.
Name:
PADCAL
Offset:
0x28
Reset:
0x0000
Access:
PAC Write-Protection
Bit15141312111098
TRIM[2:0]TRANSN[4:2]
AccessR/WR/WR/WR/WR/WR/W
Reset000000
Bit76543210
TRANSN[1:0]TRANSP[4:0]
AccessR/WR/WR/WR/WR/WR/WR/W
Reset0000000

Bits 14:12 – TRIM[2:0]: Trim bits for DP/DM

Trim bits for DP/DM

These bits calibrate the matching of rise/fall of DP/DM.

Bits 10:6 – TRANSN[4:0]: Trimmable Output Driver Impedance N

Trimmable Output Driver Impedance N

These bits calibrate the NMOS output impedance of DP/DM drivers.

Bits 4:0 – TRANSP[4:0]: Trimmable Output Driver Impedance P

Trimmable Output Driver Impedance P

These bits calibrate the PMOS output impedance of DP/DM drivers.