User Guide

PAMS
Technical Documentation
NME–3
Technical Information
Page 32
Issue 1 10/99
1. Ignition gets High
2. The Powerbuttom is pressed
3. The Supplyvoltage comes up from below 3.8V
4. PURX gets low caused by softwarecrash
Handset interface
The handset interface is implemented using the M–Bus. M–Bus is used
for Test puposes as well, but since M–Bus is a multipointbus there is no
problem in using M–Bus for multiple purposes.
For Test and Flash purposes F– and M–Bus are directly connected from
the MAD to the systemconnector. This enables us to use the common Test
and Flash utilities used for HD 941 and HD 943 for CD949 in the same
way.
Multiplexing the Busses
The M–Bus is a multipoint bus, that could be used for both purposes
(Test/Flash and Handset) without any restrictions. The F–Bus is designed
as a point to point bus, so that it is not possible to connect it to 2 parties
(Data–If and Test IF) directlly. In CD949 it is implemented in a way that
the F–Bus TX from the MAD is going to the Data interface and the Test
interface. The Signals coming from the 2 interfaces are combined by a
AND–gate before they are going to the F–BUS RX. This means that you
could try to use both interfaces at the same time without any risk of
damage to any device, but it is not possible to make data transfer via the
RS232, will using the F–Bus for test or trace purposes. This is no major
drawback, because when you are flashing or aligning the product in the
factory, you are not using the data interface, and the enduser who need s
the Data interface is not touching the test interface at all.
SIM Card in RU
Due to the fact that we are reusing the CD745 mechanical parts we have
also to reuse the CD745 SIM card reader.
Power up/Power down procedure
In the gm8b the CCONT is acting as Reset and Powercontrol Master, as
well as as watchdogtimer. In a normal handportable DCT3 phone the main
powerupprocedure works as following: The user presses the powerbutton,
this signal is delivered to the CCONT via its poweronxpin. If this signal is
valid for more then 50mS the CCONT turns on PURX in order to RESET
the MAD and handover the control to the MAD. When the phone is
switched off or the software crashes the MAD is no longer reseting the
CCONTs watchdogtimer , the watchdogtimer gives an alert, CCONT
switches PURX off and puts the phone into sleepmode.
In case of a handy its O.K. when the user has to switch on the phone
again after a softwarecrash, in a carphone (without a handset ??) he won’t
even realise that there is a problem, so this behaviour is not acceptable.