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Coldfire V1 SPI with Ublox Neo 5Q

Question asked by David Wright on May 19, 2010
Latest reply on Aug 13, 2010 by David Wright

I am working on a simple GPS implementation using a MCF51JM128 and a UBLOX neo 5q selected for its SPI capability. 


Currently the system is temperamental in that a system reset will result in either the correct data being received via the SPI port, that is a, NMEA bit stream.  Or I will receive periodic garbage in the same period as the NMEA stream.  The garbage is always the same there are about 4 variations and each is recognisable.  Further this cannot simply be a matter of selection of protocals as there are only 2 available protocals on the ublox.


I have attached a filet showing the current setup of the SPI wire connections.  The GPS chip is connected via SPI2 and uses the FIFO mode.


The following links are the code I have written for the SPI2 FIFO.  They are displayed on slexy code viewer so that the code is easier to read.  If anyone would specifically like files please ask.


SPI Functions:



My Question finally is firstly have I missed something in terms of the hardware connections?  And second is there a common problem that could cause the corruption data in the manner that I have described.