VSC8601 Datasheet
Functional Descriptions
MDC to the next rising edge of MDC. When data is being written to the PHY, it must be
valid around the rising edge of MDC.
Idle The sequence is repeated.
3.11.2
SMI Interrupts
The SMI also includes an output interrupt signal, MDINT, for signaling the station
manager when certain events occur in the PHY.
The MDINT pin can be configured for open-drain (active-low) by tying the pin to a
pull-up resistor and to VDDIO. The following illustration shows this configuration.
Figure 10.
MDINT Configured as an Open-Drain (Active-Low) Pin
VDDIO
External Pull-up
at Station Manager
for Open-Drain
(Active Low Mode)
Interrupt Pin Enable
(MII Register 25.15)
MDINT
MDINT
(to Station Manager)
Interrupt Pin Status
(MII Register 26.15)
Alternatively, each MDINT pin can be configured for open-source (active-high) by tying
the pin to a pull-down resistor and to VSS. The following illustration shows this
configuration.
Figure 11.
MDINT Configured as an Open-Source (Active-High) Pin
VDDIO
Interrupt Pin Enable
(MII Register 25.15)
MDINT
(to Station Manager)
MDINT
Interrupt Pin Status
External Pull-Down at
Station Manager
(MII Register 26.15)
for Open Source
(Active-High Mode)
When a PHY generates an interrupt, the MDINT pin is asserted (driven high or low,
depending on resistor connection) if the interrupt pin enable bit (MII Register 25.15) is
set.
Revision 4.1
September 2009
Page 27
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