User Manual

ZSTAR3 Sensor Board Description

ZSTAR3 Reference Design Manual, Rev. 0.1

3-22 Freescale Semiconductor

Preliminary

header for regular BDM re-programming. The pin numbering is shown on Figure 3-5. - BDM Connector

Layout

Figure 3-5. BDM Connector Layout

3.3.5 Button Connections

Three buttons (S1, S2 and S3) are connected directly to pins PTA0, PTA6 and PTA7. All have internal

pull-up resistors, and are part of the Keyboard Interrupt module, therefore allow a direct microcontroller

wake-up from the Stop modes.

3.3.6 MC13213 RF Interface

The RF interface (antennas) were designed with the cost and board size in mind. Among several designs,

the PCB layout antennas were in the main consideration (cost). Of several PCB antenna designs available

for the 2.4GHz band (F-antenna, dipole, loop), the loop antenna has been selected mainly because of the

size required on the PCB.

The MC13213 transceiver provides a internal antenna switch of RF IN (receive) and PA OUT (transmit)

paths, thus can be use a simple loop antenna.

The antenna is designed as a “smile” layout , 10.7x24.3mm (420x960mils), made of 1.25mm (50mils)

wide trace of copper.