PDSP16350 Datasheet, PDF (10/13 Pages) Mitel Networks Corporation – I/Q Splitter/NCO

PDSP16350
Modulated Phase
Relative phase jumps may be made with or without ampli-
tude modulation. For example, if a jump of 180 degrees is
required, this can be done with a value of :
DIN33:0 = 10 0000 0000 0000 0000 0000 0000 0000 0000
This is loaded into the phase increment register for one
cycle, then the normal increment value is re-loaded in the
following cycle.
Alternatively, if no amplitude modulation is needed, an
absolute jump to a phase value can be made, see Fig. 9. This
can be done by activating the JUMP input during one cycle and
also presenting the new phase value at the same time. For
example, if a jump to 270 degrees is required :
DIN33:0 = 11 0000 0000 0000 0000 0000 0000 0000 0000
The RES (reset) input can alternatively be used if a jump
to 0 degrees is needed. This avoids using the DIN inputs and
can be used with or without amplitude modulation. The reset
function is internally synchronised to the input clock.
N
ABCD
T
Device Reset Apply First
Data
Absolute Phase
Jump
ABC
First Result
Available
Absolute phase
jump result
Fig. 9 Phase Modulation Timing Diagram
9