hsp50214a Intersil Corporation, hsp50214a Datasheet - Page 48

• Manufacturer Part Number: hsp50214a
• Description: Programmable Downconverter
• Manufacturer: Intersil Corporation

POSITION
POSITION
31-22
14-11
31-30
28-16
15-12
11-8
BIT
BIT
7-0
7-4
3-0
21
20
19
18
17
16
15
10
29
9
8
Reserved
Enable External
Filter Sync
Halfband (HB)
Bypass
HB5 Enable
HB4 Enable
HB3 Enable
HB2 Enable
HB1 Enable
FIR Decimation
FIR Real/Complex
FIR Sym Type
FIR Symmetry
FIR Taps
Reserved
Sync AGC Updates
to SYNCIN2
Threshold
Loop Gain 1
Mantissa
Loop Gain 1
Exponent
Loop Gain 0 Mantissa
Loop Gain 0
Exponent
FUNCTION
FUNCTION
CONTROL WORD 7: HB, FIR CONFIGURATION (SYNCHRONIZED TO PROCCLK)
CONTROL WORD 8: AGC CONFIGURATION 1 (SYNCHRONIZED TO PROCCLK)
Reserved.
0- The SYNCIN2 pin has no effect on the halfband and FIR filters.
1- When the SYNCIN2 pin is asserted, the filter control circuitry in the halfband filters, the FIR,
the resampler, and the discriminator are reset. SYNCIN2 can be used to synchronize the com-
putations of the filters in multiple parts for the alignment (see Synchronization Section).
1- Bypass Halfband Filters.
0- Enable HB Filters (at least one HB must be enabled).
0- Disables HB number 5 (the last in the cascade).
1- Enables HB filter number 5.
Setting this bit enables HB filter number 4.
Setting this bit enables HB filter number 3.
Setting this bit enables HB filter number 2.
Setting this bit enables HB filter number 1.
Load decimation from 1-16, where 0000 = 16. Bit 14 is the MSB.
0- Complex Filter.
1- Dual Real Filters.
0- Odd Symmetry.
1- Even Symmetry.
0- Symmetric Filters.
1- Asymmetric Filters.
Number of taps in the FIR filter. Range is 1 to 255, where 0000000 is invalid.
Reserved.
When this bit is 1, the SYNCIN2 pin loads the contents of the master registers into the AGC
accumulator.
The magnitude measurement out of the cartesian to polar converter is subtracted from this val-
ue to get the gain error. A gain of 1.647 in the cartesian to polar conversion that must be taken
into account when computing this threshold. These bits are weighted -2
the MSB.
Selected when AGCGNSEL = 1. These bits, MMMM, together with the exponent bits, EEEE
(11-8), set the loop gain for the AGC loop. The gain adjustment per output sample is:
1.5dB (Threshold -[Magnitude * 1.6]) 0.MMMM * 2
to 1.414 and the threshold is programmed in bits 28-16. The decimal value for the mantissa is
calculated as DEC(MMMM)/16. Bit 15 is the MSB.
Selected when AGCGNSEL = 1. These bits are EEEE. See description of bits 15-12. Bit 11 is
the MSB.
Selected when AGCGNSEL = 0. These bits are MMMM. See description for bits 15-12. Same
equations are used for Loop 0. Bit 7 is the MSB.
Selected when AGCGNSEL = 0. These bits are EEEE. See description for bits 15-12. Same
equations are used for Loop 0. Bit 3 is the MSB.
HSP50214A
48
DESCRIPTION
DESCRIPTION
-(15 - EEEE)
where magnitude ranges from 0
2
down to 2
-10
. Bit 28 is