PDSP16330/A/B

CEX

FORM

S0

S1 2

X15:0

Y15:0

16

SIGN

MAGNITUDE

15

X2

30

+

32

X2 + Y2

16

SHIFT

CEY

16 16

MAGNITUDE

15

Y2

30

SIGN

X>Y

SIGN X

Y/X

9

π /4

ARCTAN

ROM

SIGN Y

9

ROTATE

12

OEM

OEP

M15:0

OVR

P11:0

FUNCTIONAL DESCRIPTION

Fig.2 Block diagram

The PDSP16330 converts incoming Cartesian Data

into the equivalent Polar Values. The device accepts new 16

+ 16 bit complex data every cycle, and delivers a 16 bit + 12

bit Polar equivalent after 24 clock cycles.The input data can be

in 2s’ Complement or Sign Magnitude format selected via the

FORM input. The output is in a magnitude format for both the

Magnitude output and the Phase. Phase data is zero for data

with a zero Y input and positive X, and is 400 hex for zero X

data and positive Y, is 800 hex for zero Y data and negative X,

and is C00 hex for zero X and negative Y. The LSB weighting

(bit 0) is 2 x π/4096 radians. The 16 bit Magnitude result may

be scaled by shifting one, two, or three places in the more

significant direction, effectively multiplying the Magnitude

result by 2,4 or 8 respectively. Any of these shifts can under

certain conditions cause an invalid result to be output from the

device. Under these circumstances the OVR output will

become active. The PDSP16330 has independent clock

enables and three state output controls for all ports.

FORM

S1-0

These inputs select the scaling factor to be applied to

the Magnitude output. They are latched by the rising edge of

CLK and determine the scaling of the output in the cycle after

they are loaded into the device. The scale factor applied is

determined by the table. Should the scaling factor applied

cause an invalid Magnitude result to be output on the M Port,

then the OVR Flag will become active for the period that the

M Port output is invalid.

S1 S0

00

01

10

11

Scaling Factor

x1

x2

x4

x8

This input selects the format of the X and Y input data.

A low level on FORM indlcates that the Input data is twos’

complement format (Note: input data 8000 hex is not valid in

2s’ complement mode). This input refers to the format of the

current Input data and may be changed on a per cycle basis

if desired. The level of FORM is latched at the same time as

the data to which it refers.

The output number range is from 0 to 2 when the

scaling factor is set at x1.

2