GC5016 Datasheet, PDF (60/88 Pages) Texas Instruments – WIDEBAND QUAD DIGITAL DOWN CONVERTER/ UP CONVERTER

GC5016
SLWS142G − JANUARY 2003 − REVISED NOVEMBER 2005
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It is important that the synchronization source has an active SYNC signal when the Reset signal is released during
the initial GC5016 programming.
Repetitive synchronization, if used, requires a logic low Sync input that is one CK period wide.
The cmd5016 programming software has a pseudo-command ’sync_mode’. The sync_mode is used to set up
common synchronization modes for all of the sync registers. It has the added benefit of adding the assert-sync,
remove-reset, and remove-sync. See the Programming GC5016 application note for more information on this
command and its use.
The sync_mode keyword can accept the following values:
0, SIA selected for sync source
1, SIB selected for sync source
4, One Shot Sync Out, (external SOB to SIA) connected to SIA, level
5, One Shot Sync Out, (external SOB to SIA) connected to SIA, pulse
6, One Shot Sync Out, (external SOB to SIB) connected to SIB, level
7, One Shot Sync Out, (external SOB to SIB) connected to SIB, pulse
8, internal one shot, level triggered
9, internal one shot, pulse triggered
16.9 Initialization
Three initialization procedures are recommended. The first is for standalone GC5016 chips, the second is for a
multi-GC5016 chip configuration synchronized by a master GC5016 chip, and the third is for a configuration where
the GC5016s are to be synchronized by to an external source.
16.9.1 Standalone GC5016 Chips
This procedure works if the GC5016 can free run and its timing doesn’t need to be synchronized with other chips
(FPGAs, other GC5016s, etc.).
1. Reset the chip by writing 0xFF00 to address 0.
2. Disable all outputs by writing 0 to address 3.
3. Force the one-shot to be a pulse by writing 0x04 to address 1.
4. Load the configuration generated by the cmd5016 program.
NOTE:All sync controls that need to select a sync source should be set to 4, (one shot).
This can be done by adding these lines to the cmd5016 input file:
soB_sync 4
fir_sync 4
sck_sync 4
nco_sync 4
cic_sync 4
5. Clear the reset by writing 0x100 to address 0.
6. Pulse the syncs by writing 0x04 to address 1
NOTE:The above procedure is selected by setting pseudo-command sync_mode to ’9’.
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