Specifications

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SLWS142J − JANUARY 2003 − REVISED AUGUST 2007
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50
sum_selI
a
b
Asum
c
Bsum
d
sum_selQ
a
b
Asum
c
Bsum
d
Mux,
Round,
Delay
Mux,
Round,
Delay
sumin
DO CO
sum_ia
sum_ib
sum_qa
sum_shift
sum_qb
Mux,
Round
Mux,
Round
toutf_rnd_AB
toutf_halfcmplx_AB
toutf_quiet_AB
ia
AO
qa
ib
qb
BO
Transmit
Output
Mux
ic
id
CO
DO
toutf_rnd_CD
toutf_halfcmplx_CD
toutf_quiet_CD
toutf_bo
toutf_co
toutf_do
toutf_hold
toutf_offsetbin
Figure 26. Transmit Sum and Output Format Details
14.10.1Sum Selection
Data from the four complex mixers (mixA−D) is sent to sum and selection blocks. The I data from the four mixers
is combined (controlled by sum_selI) into two outputs, Asum and Bsum. Likewise, Q data is combined (controlled
by sum_selQ). The sum_selI and sum_selQ controls are 8-bit values with bits (s7..0). The Asum output is:
Sum Select setting:
Asum = s0 x (s1 x a + s2 x b + s3 x c) + s4 x (s5 x d + s6 x b + s7 x c)
The Bsum output is:
Bsum = s5 x d + s6 x b + s7 x c.
Table 4 shows four common configurations. There is a constraint that s2 and s3 may not both be one. Likewise for
s6 and s7.