GC5018_06 Datasheet, PDF (114/134 Pages) Texas Instruments – 8-CHANNEL WIDEBAND RECEIVER

GC5018
8-CHANNEL WIDEBAND RECEIVER
SLWS169A – MAY 2005 – REVISED NOVEMBER 2005
4.4.5.27 DDCCONFIG1 Register
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Register name: DDCCONFIG1
BIT 15
0
BIT 7
0
ddcmux_sel_a (3:0)
0
0
ddcmux_sel_b(3:0)
0
0
Page: 0x0%00
where:
% = 2×(DDC channel #)+1
Address: 0x1A
agc_rnd_
disable
gain_mon
0
0
0
remix_only
cic_ bypass
0
0
0
BIT 8
ch_rate_sel(1:0)
0
0
BIT 0
double_tap(1:0)
0
0
ddcmux_sel_X(3:0) : Controls which samples go to the mixer for I/Q. Since in CDMA there are two
streams, an A and B stream, two mux select values are used.
Select Value
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
I data from X input
RXINA
RXINB
RXINC
RXIND
RXINA
RXINA
RXINA
RXINB
RXINB
RXINB
RXINC
RXINC
RXINC
RXIND
RXIND
RXIND
Q data from X input
RXINA
RXINB
RXINC
RXIND
RXINB
RXINC
RXIND
RXINA
RXINC
RXIND
RXINA
RXINB
RXIND
RXINA
RXINB
RXINC
agc_rnd_disable : When set, the agc_rnd bits have no effect. The whole 29 bits are used in the rounding
and the round bit is bit4.
gain_mon : Combines the gain with the I/Q output signals when asserted.
OUTPUT
I
Q
Bits(17:10)
Gained I value
Gained Q value
Bits(9:4)
Gain(10:5)
Bits(3:2)
Gain(18:11)
Shift status(1:0)
Bits(1:0)
"00"
"00"
ch_rate_sel(1:0) : Sets the DDC channel input data rate. The value set here should match the value in
the Receive Input Interface rate select bits (rate_sel).
114 GC5018 GENERAL CONTROL
ch_rate_sel
00
01
10
11
Input data rate
rxclk
rxclk/2
rxclk/4
rxclk/8