UM0896
Configuration
Doc ID 17009 Rev 1
11/43
This strapping option pair determines the operating mode of the MAC data interface. Default
operation (no pull-ups) will enable normal MII mode of operation. Strapping CFG0 high will
cause the device to be in RMII mode of operation, determined by the status of the CFG1
strap. Since the pins include internal pull-downs, the default values are 0.
Note:
Important:
To choose between MII and RMII the pin RXDV of the PHY must be pulled high
for RMII and pulled low for MII during reset or power-up of the PHY.
5.2 Power
supply
The STEVAL-PCC012V1 demonstration board is designed to be powered by a 24 V DC
power supply from CN2, P2. The board is protected against overvoltage by D4 Transil™
diode (SM6T33A) and against possible reverse polarity voltage from a wrong power plug-in
by D1 Schottky diode (STPS3L40U). The input voltage is connected to the DC/DC converter
U2 (L7986A).
Table 4.
Logical levels on CFG0, CFG1
Jumper
Description
Configuration
CFG0
(3-pin resistor)
(2.2 k
Ω
)
CFG0 = 0,
default
The resistor must be placed as shown:
CFG0 = 1
The resistor must be placed as shown:
CFG1
(3-pin resistor)
(2.2 k
Ω
)
CFG1 = 0,
default
The resistor must be placed as shown:
CFG1 = 1
The resistor must be placed as shown:
Table 5.
Ethernet PHY configuration defined by CFG0, CFG1
Function
CFG0
CFG1
MII
0
X
RMII
1
0
Table 6.
U2 DC/DC converter jumpers
Jumper
Description
Configuration
R4
To run DC/DC U2 on higher frequency R4 must be
assembled with 102 k
Ω
resistor. Other components
of the DC/DC must be changed accordingly.
(
Default - not assembled
)
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