PDSP16116 Datasheet, PDF (12/18 Pages) Mitel Networks Corporation – 16 X 16 Bit Complex Multiplier

PDSP16116/A/MC
AR
SOBFP
AR15:13
EOPSS
BR
BI
WR
WI
A
XR XI YR YI
WTA WTB
AI
AI15:13
A
PDSP1601/A
SFTA
C
PDSP16116/A
PR
PI
PDSP1601/A
SFTA
C
DAR
DAI
A
B
PDSP16318/A
SFTR
C
D
B
A
PDSP16318/A
SFTR
C
D
A'R
A'I
WTOUT
GWR
B'R
B'I
Figure 5 - FFT Butterfly Processor
At the end of each constituent pass of the FFT, the
positions of the binary point supported may change to reflect
the trend of data increase or decreases in magnitude. Hence,
in the pass following that of the above example, the four
positions of binary point supported may be change to:
XX.XXXXXXXXXXXX
XXX.XXXXXXXXXXX
XXXX.XXXXXXXXXX
XXXXX.XXXXXXXXX
word tag = 00
word tag = 01
word tag = 10
word tag = 11
This variation in the range of binary points supported from
pass to pass (i.e. the movement of the binary point relative to
its position in the original data) is recorded in the GWR.
Thus we can determine the position of the binary point
relative to its initial position by modifying the value of GWR by
WTOUT for a given word as shown in Table 6.
As an example, if GWR=01001 and WTOUT=10 then the
binary point has moved 10 places to the right of its original
position.
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