HSP50214BVCZ datasheet(33/62 Pages) RENESAS

33 / 62 page

HSP50214B

FN4450 Rev 4.00

Page 33 of 62

May 1, 2007

Data Ready Signal Assertion Rate:

The assertion rate of the DATARDY signal Is the data

transition rate of the AOUT 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 ø 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: The number of PROCCLKS per output symbol is not representative, but shown to be small for clarity of establishing timing with respect 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

 are sample aligned in time, but one sample delayed from I or Q. The frequency sample

is delayed in time from I or Q by 1 sample time + 63 tap FIR impulse response. If the FIR is set to decimate and frequency 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

I3I4

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

AOUT

PROCCLK

DATARDY

f0 (R = 4)

DR0

BOUT

Qn+1

Qn+2

1 + FIR Delay

DR-1

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