Silicon Laboratories C8051F540DK, User Manual

C 8 0 5 1 F 5 4 0 D K

14

Rev. 0.1

7.11.  Power Supply I/O (Side A) (TB3)

All of the C8051F540 target device’s supply pins are connected to the TB3 terminal block. Refer to Table 8 for the
TB3 terminal block connections.

7.12.  Alternate Power Supply Headers (J15, J18)

The C8051F540 Target Board includes two headers that allow for alternate power sources and power
measurement. Header J15 connects the VIO voltage supplied to the Side A MCU to other peripherals on the board,
such as the P1.4_SW push-button switch pull-up, and the R17 potentiometer source. To enable current
measurement, the shorting block on J15 can be removed so that the VIO_A node only powers the VIO pin on the
MCU. Another voltage source will need to be applied to the VIO_SRC node to power the other peripherals.

Header J18 connects the P4 power-adapter supply to the V_HIGH node, which is used as the power source for the
LIN transceivers (T1, T2). The shorting block on header J18 can be removed to force the LIN transceivers to use
the voltage supply externally supplied on the +LIN_V pin on the TB1 header.

7.13.  C2 Pin Sharing

On the C8051F540 (Side A), the debug pins C2CK and C2D are shared with the pins RST and P2.1, respectively.
On the C8051F542 (Side B), the debug pins C2CK and C2D are shared with the pins RST and P2.1, respectively.
The target board includes the resistors necessary to enable pin sharing which allow the pin–shared pins (RST and
P3.0) to be used normally while simultaneously debugging the device. See Application Note “AN124: Pin Sharing
Techniques for the C2 Interface” at 

www.silabs.com

 for more information regarding pin sharing.

Table 8. TB3 Terminal Block Pin Descriptions

Pin #

Description

1

VIO_A

2

VREGIN_A

3

VDD_A

4

VDDA_A

5

GNDA_A

6

GND