Address offset: 0x464
The RTUNE mode is an alternative method for calibrating the DP and DM 45-Ohm source impedance.
When this method is used, the USBHS REXT resistor does not need to be connected and can be left floating. This RTUNE mode is selected by setting RTUNESEL to 0, and the tune calibration value is set by the RCALCODE input bus.
| 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 | |||
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| ID | B | B | B | B | A | ||||||||||||||||||||||||||||||
| Reset 0x0000000F | 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 | 1 | 1 | 1 | 1 | |||
| ID | R/W | Field | Value ID | Value | Description | ||||||||||||||||||||||||||||||
| A |
RW |
RTUNESEL |
This signal selects the tuning method for the high-speed DP and DM source impedance of the USBHS. |
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|
TXRTUNE |
1 |
The TXRTUNE pin, external resistor REXT, and resulting internal digital calibration code are used for tuning the high-speed source impedance. |
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|
RTUNE |
0 |
The RCALCODE value is used for tuning the high-speed source impedance. |
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| B |
RW |
RCALCODE |
This signal is used to tune the internal 200 ohm resistor or the USBHS DP and DM high-speed source impedance. All values from 4'b1111 to 4'b0000 are valid. A value of 4'b1111 provides the lowest impedance on DP/DM, and a value of 4'b0000 provides the highest impedance on DP/DM |
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