Sundance FC100 - Manual (Page 10)

5 Critical signal descriptions
All interface and internal operation of the core is synchronous to CLK. Simple SYNC strobes
are used on the input and output interfaces to signal that data is valid on the following clock
cycle. An active SYNC coinciding with the last data point thus indicates back-to-back
transforms. A SYNC_IN strobe active while the core is already inputing data is ignored.
Tying SYNC_IN active will signal the core to perform continuous transforms, and
SYNC_OUT will strobe as normal to frame the output data.
Figure 1: Interface input timing, 1K-length back-to-back transforms
Figure
Figure 2: Interface Output Timing, 1K-length back-to-back transforms
The DIR and SEL configuration inputs are by default selectable per-transform, but must be
stable starting with SYNC_IN active and must not be changed until the transformed data has
been completely output from the core (i.e. 2
m
clocks after the corresponding SYNC_OUT).
User Manual FC100 Page 10 of 12 Last Edited: 25/11/2008 15:00:00