Fmtx 2.1 Pwb Traces; Specific Digital And Power Supply Test Points - Nokia RM-333 Service Manual

FMTx 2.1 PWB traces

Specific digital and power supply test points

Using access to signals figure as a reference it can be seen that supplies to the Si4713 device VIO (pin 10) and
VDD (pin 11) can be accessed easily. The FMTx 2.1 solution utilises a QFN package. This type of package lends
itself well to analysis of signals on the various pins of the device.
VIO & VDD
VIO should be in the range 1.5 to 3.6 Volts.
VDD should be in the range 2.7 to 5.5 Volts.
_RST
Also, the _RST signal to the device can be monitored. This is an active low signal and should only be asserted
during power up. The _RST signal is driven by the PURX line.
The state of pins 19 & 18 (GPO1 and GP02 respectively) on the rising edge of the _RST pin determines what
interface is selected when the device powers up.
Bus Name Bus Mode
I2C 2-Wire
SPI
CBus 3-Wire
It's possible that if GP01 and/or GPO2 are not at the correct state when the Si4713 device has power applied
then the wrong bus mode could be selected and the handset would be unable to communicate with the
device. For RM-333, the bus mode should be I2C.
Page 7 –6
Figure 55 FMTx 2.1 layout
Table 6 Bus mode selection truth table
GPO1
High
SPI High
Low (must
drive)
COMPANY CONFIDENTIAL
Copyright © 2008 Nokia. All rights reserved.
GPO2/IRQ
Low
Low (must drive)
Low
RM-333; RM-334; RM-335
FMTx 2.1 Troubleshooting
Issue 2