ISL5217 Datasheet, PDF (28/43 Pages) Intersil Corporation – Quad Programmable Up Converter

ISL5217
TABLE 16. I CHANNEL INPUT OR FM (15:0)
TYPE: SINGLE CHANNEL DIRECT, ADDRESS: 0x00
BIT
FUNCTION
DESCRIPTION
15:0 I Channel QASK Input or I(15:0). In QASK mode, this is the I input vector. The format is 2’s complement. The MSB is bit 15. The
FM Input
mixer operation is:
OUT = (I*COS) - (Q*SIN).
In FM mode, this is interpreted as an offset frequency to the center frequency. The modulation index
depends on the mode and the filter coefficients. In FM with post filter mode, the phase change per input
sample can range from -180 to 180 degrees, so the deviation is limited to ±(input sample rate)/2.
TABLE 17. Q CHANNEL INPUT (15:0)
TYPE: SINGLE CHANNEL DIRECT, ADDRESS: 0x01
BIT
FUNCTION
DESCRIPTION
15:0
Q Channel Input
Q(15:0). In QASK mode, this is the Q input vector. See address 0 above. In FM mode, this input is not
used.
NOTE: Writing to the I channel input generates the update strobe to move the data into the IQ FIFO. Normal write order is Q then I.
BIT
FUNCTION
15:0 Fixed Integer Divider
TABLE 18. FIXED INTEGER DIVIDER, MSW
TYPE: SINGLE CHANNEL DIRECT, ADDRESS: 0x02
DESCRIPTION
FID(31:16) is loaded in this address. See Address 3.
TABLE 19. FIXED INTEGER DIVIDER, LSW
TYPE: SINGLE CHANNEL DIRECT, ADDRESS: 0x03
BIT
FUNCTION
DESCRIPTION
15:0 Fixed Integer Divider
FID(15:0) is loaded in this address. The fixed integer divider is a 32 bit counter clocked at the output clock
rate. The carryout is used to clear the fine and /or coarse phase of the sample rate NCO. Allows fixed
integer sample rates. The fixed integer divider is computed by the formula:
FID (31:0) = INT [fCLK/ fCO]
NOTE: Writing to the LSW generates the update strobe to load the slave configuration reg when in the immediate mode
BIT
FUNCTION
15:0
Sample Rate NCO
TABLE 20. SAMPLE FREQUENCY (47:32) MSW
TYPE: SINGLE CHANNEL DIRECT, ADDRESS: 0x04
DESCRIPTION
SF(47:32) is loaded in this address. See Address 6.
BIT
FUNCTION
15:0 Sample Rate NCO
TABLE 21. SAMPLE FREQUENCY (31:16)
TYPE: SINGLE CHANNEL DIRECT, ADDRESS: 0x05
DESCRIPTION
SF(31:16) is loaded in this address. See Address 6.
TABLE 22. SAMPLE FREQUENCY (15:0) LSW
TYPE: SINGLE CHANNEL DIRECT, ADDRESS: 0x06
BIT
FUNCTION
DESCRIPTION
15:0 Sample Rate NCO
SF(15:0) is loaded in this address. The sample rate is controlled by a 48-bit NCO clocked at the output
clock rate. The sample rate is computed by the formula:
SF (47:0) = INT [(f_s / f_CLK) * 2 ⁴⁸]
NOTE: Writing to the LSW generates the update strobe to load the slave configuration reg when in the immediate mode.
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