GPS Free Stack/Notes About Milkymist
Currently using/borrowed address space from the softusb core, later the plan will be properly add a gps baseband slave core and send to upstream
DCM is set to x4 clock input
Namuru sampling is adjusted to sample every 1 of 4 samples as real data is provided in parallel not serialized.
Milkymist SoC uses external clock input from GPS Receiver IC to make things easier.
[edit] Interfacing
Currently the SiGe SE4162T-EK is interfaced with the Milkymist One board trough the expansion header J21 and memory card reader test point as follows:
SE4162T-EK1 EVB Milkymist One J4 Pin 1 VBAT .................................... J21 Pin 3 3V3 J4 Pin 3 SYNC ------------------------------------ J21 Pin 7 A20 J4 Pin 4 DATA .................................... J21 Pin 9 A21 J4 Pin 5 CLK_OUT ------------------------------------ TP 19 CLK A10 J4 Pin 8 GND .................................... J21 Pin 17 GND J5 ANT (to active GPS External Antenna)
Clock input is wired to memcard as exp header lacks a dedicated clock route.
SiGE EVB Jumper positions:
J1 2<->3 Fit J9 1<->2 FIT R4 0 = 0R
This setup allow the use of the on-board regulator (wich is not the internal LDO from SiGE chip). (LDO still need to be tested) (LNA still need to be tested)
Optional Debug Signals on EVB:
J4 Pin 10 Vdd (Expected 2V9~ in normal operation) J4 Pin ANT_DET (Expected 3V3~ When External ANT connected)}
Real Mode (current mode) More generic mode, no relay single chip, not saying complex is not better, just lacking support in both osgps and namuru
R9 = 47K to R14.