8

PLUTO

PROGRAMMING and CONTROL

The control modes for Pluto can be set via external pins or via a 3 wire serial interface. On initialising Pluto control is from

external pins but can then be set for programming from the serial interface by setting the appropriate bit in a serial input word.

The Rx second LO synthesiser is programmed via the serial interface: the Tx IF synthesiser is fixed and requires no programming.

SLEEPB

FMB

IDLEB

Mode

(Pin 9)

(Pin 7)

(Pin 5)

0

X

X

Sleep Mode

1

0

0

FM Receive only

1

0

1

FM Receive and Transmit

1

1

0

CDMA Receive only

1

1

1

CDMA Receive and Transmit

Mode Control - External

The control modes are set by the pins SLEEPB, FMB and IDLEB as shown in the table below:

Aux ADC Selection - External

The auxiliary analog to digital converters can be selected via pins S0 and S1 as shown in the table below:

S1

S0

ADC

(Pin 39)

(Pin 33)

selected

0

0

ADC<0>

0

0

ADC<1>

1

0

ADC<2>

1

1

ADC<3>

ADC selection can also be programmed to be via serial interface if required

Serial Interface

The 3 wire serial interface (SDATA, SCLK and SLATCH) is programmed using 24 bit words as shown below. Timing

details are shown in Figure 8.

MSB

LSB

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9876543210

WORD1

00000

X

X

RXC

RXDIV<13:0>

0

0

WORD2

SOP FMB IDB SLB

000000

AD1 AD0 TST

00000

MXS CTB

0001

X

unused

RXC

RX Synth comparison frequency :0 = 30kHz, 1 = 5kHZ

RXDIV<13:0>

RX Synth divider ratio

SOP

External/ Serial mode selection: 0 = Ext, 1 = Serial

SLB, IDB, FMB

Sleep, Idle and FM mode control bits (serial mode)

TST

Test Mode Control - This is for test purposes only and should be set to 0

AD1, AD0

Aux ADC select bits (serial mode)

MXS

External / Serial Aux ADC select: 0 = Ext

CTB

Enable Rx Calibration: 0 = calibration mode

If SOP is high mode control is via serial bits FMB, IDB and SLB, instead of external pins FMB, IDLEB and SLEEPB.

If MXS is high then ADC selection is via AD1, AD0 instead of S<1>, S<0>