![](http://datasheet.mmic.net.cn/370000/HSP50214B_datasheet_16695388/HSP50214B_33.png)
3-33
Data Ready Signal Assertion Rate:
The assertion rate of the DATARDY signal Is the data
transition rate of the A
OUT
output data either [I, |r| or f]. The
time alignment of parallel data words available for output are
as follows:
I and Q are aligned in time,
|r| and are time aligned, but one sample clock delayed
from the associated I and Q samples.
DATARDY Is asserted time aligned with and at the same
rate as the data type selected for the AOUT output.
Figure 31 details the timing of the AOUT and DATARDY for
an AOUT = I data selection.
Note that the BOUT data word may be at a different rate and
skewed in time with respect to DATARDY, depending on the
type of data selected for output. This is because of the timing
relationships defined above, and because the DATARDY is
driven by the AOUT signal. Figure 32 details such a
configuration.
When the f (frequency) word is selected for output on AOUT,
the DATARDY signal is asserted at the discriminator FIR filter
output rate, which will be a reduced rate when decimation is
engaged in the filter. The f (frequency)S output is delayed
from the associated I and Q samples one sample time plus,
the discriminator FIR filter impulse response time. Figure 33
details the timing of this configuration for a FIR filter that
decimates by 4.
NOTE: ThenumberofPROCCLKSperoutput symbolisnot representative,butshowntobesmallforclarity ofestablishingtimingwithrespect
to the DATARDY signal. For each application, the relationship of the output symbol rate to PROCCLK must be properly illustrated to determine
the exact nature of the timing.
FIGURE 31. DATARDY WAVEFORMS WHEN I (READ DATA) IS SELECTED AS AOUT
FIGURE 32. DATARDY WAVEFORMS WHEN |r| (MAGNITUDE) IS SELECTED AS AOUT
NOTE: I and Q are sample aligned in time. |r| and
φ
are sample aligned in time, but one sample delayed from I or Q. The frequency
sampleisdelayedintimefromIorQby1sampletime+63tapFIRimpulseresponse.IftheFIRissettodecimateandfrequency
is selected for AOUT, the DATARDY signal will be at the discriminator FIR output (decimated) rate.
FIGURE 33. DATARDY WAVEFORMS WHEN f (FREQUENCY) IS SELECTED AS AOUT
AOUT
PROCCLK
DATARDY
I0
I1
I2
I3
I4
I5
I6
DR0
DR1
DR2
DR3
DR4
DR5
DR6
AOUT
PROCCLK
DATARDY
|r|0
|r|1
|r|2
|r|3
|r|4
|r|5
|r|6
DR0
DR1
DR2
DR3
DR4
DR5
DR6
BOUT
Q0
Q1
Q2
Q3
Q4
Q5
Q6
AOUT
PROCCLK
DATARDY
f0 (R = 4)
DR0
BOUT
Q0
Q1
Q2
Q3
Q4
Qn
Qn+1
Qn+2
1 + FIR Delay
DR-1
HSP50214B