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* Microsemi - vsc8531 Giga bit ethernet phy
Required properties:
- compatible : Should contain phy id as "ethernet-phy-idAAAA.BBBB"
The PHY device uses the binding described in
Documentation/devicetree/bindings/net/phy.txt
Optional properties:
- vsc8531,vddmac : The vddmac in mV. Allowed values is listed
in the first row of Table 1 (below).
This property is only used in combination
with the 'edge-slowdown' property.
Default value is 3300.
- vsc8531,edge-slowdown : % the edge should be slowed down relative to
the fastest possible edge time.
Edge rate sets the drive strength of the MAC
interface output signals. Changing the
drive strength will affect the edge rate of
the output signal. The goal of this setting
is to help reduce electrical emission (EMI)
by being able to reprogram drive strength
and in effect slow down the edge rate if
desired.
To adjust the edge-slowdown, the 'vddmac'
must be specified. Table 1 lists the
supported edge-slowdown values for a given
'vddmac'.
Default value is 0%.
Ref: Table:1 - Edge rate change (below).
Table: 1 - Edge rate change
----------------------------------------------------------------|
| Edge Rate Change (VDDMAC) |
| |
| 3300 mV 2500 mV 1800 mV 1500 mV |
|---------------------------------------------------------------|
| 0% 0% 0% 0% |
| (Fastest) (recommended) (recommended) |
|---------------------------------------------------------------|
| 2% 3% 5% 6% |
|---------------------------------------------------------------|
| 4% 6% 9% 14% |
|---------------------------------------------------------------|
| 7% 10% 16% 21% |
|(recommended) (recommended) |
|---------------------------------------------------------------|
| 10% 14% 23% 29% |
|---------------------------------------------------------------|
| 17% 23% 35% 42% |
|---------------------------------------------------------------|
| 29% 37% 52% 58% |
|---------------------------------------------------------------|
| 53% 63% 76% 77% |
| (slowest) |
|---------------------------------------------------------------|
Example:
vsc8531_0: ethernet-phy@0 {
compatible = "ethernet-phy-id0007.0570";
vsc8531,vddmac = <3300>;
vsc8531,edge-slowdown = <7>;
};
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