ISL5217 Datasheet, PDF (31/43 Pages) Intersil Corporation – Quad Programmable Up Converter

ISL5217
TABLE 29. FIR CONTROL
TYPE: SINGLE CHANNEL DIRECT, ADDRESS: 0x0d
BIT
FUNCTION
DESCRIPTION
15
Gain Profile Mode
Enables gain profile to slew gain value during transitions of TX enable
14
Clear Sample Phase
When enabled will clear sample phase on immediate update of sample frequency
0 = maintain sample phase
1 = clear sample phase.
13
FM_Mode Disable
Set to 1 to disable the internal FM_Mode signal to the serial interface block. This keeps the I/Q input
sample alignment such that the serial interface block expects both the I and Q time slot counters to count
down to 0 prior to transferring the I/Q samples to the FIFO. Loss of synchronization of the I/Q samples
can occur when switching FM modes without this bit set.
12
Fixed Integer Mode
Enables the fixed integer divider in the sample rate NCO
11:10 Phase Offset (1:0)
The phase accumulator of the sample rate NCO can be offset by increments of 90 degrees.
00 = 0⁰
01 = 90⁰
10 = 180⁰
11 = 270⁰
9
Half Band Filter Enable 0=Half Band filter bypassed (default).
1=Half Band filter enabled.
8
Coefficient Switch
Selects second filter coefficients in coefficient RAM.
7:4
Data Span (3:0)
Data Span(3:0). Number of data samples in shaping filter, 4-16. Load with number of data samples minus
1.
3:2 Modulation Type (1:0) Modulation type(1:0)
00 = QASK - PSK or QAM modulation.
01 = FM post-filtering - Analog FM modulation. Filtering after FM modulation (baseband filtering provided
before ISL5217). In this mode both I and Q filters are used.
10 = FM pre-filtering - FSK, GMSK modulation. Filtering before FM modulation. In this mode, only the I
filter is used.
11 = Invalid state.
1:0
Interpolation Phases
Interpolation Phases(1:0) Number of coarse interpolation phases:
(1:0)
00 = forces coarse and fine phase to zero.
01 = 4.
10 = 8.
11 = 16.
NOTES:
21. QASK mode data flow - FIFO -> shaping filter -> interpolating filter
22. FM post mode data flow - FIFO -> FM modulator -> shaping filter -> interpolating filter
23. FM pre mode data flow - FIFO -> shaping filter -> FM modulator -> interpolating filter
24. The Q FIFO is not used when in the FM mode.
BIT
FUNCTION
15
PN-Generator
14:11
10
9
8
7
6
Reserved
Serial Control,
I and Q Time Slot
FIR control
Gain
Carrier Phase
Carrier Freq
TABLE 30. UPDATE MASK
TYPE: SINGLE CHANNEL DIRECT, ADDRESS: 0x0e
DESCRIPTION
1 = update, 0 = no update. PN-Generator is synchronously reset via the channel 0 UPDX signal anded
with this mask bit.
Not Used.
1 = Update, 0 = No Update.
31