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STLC1511

During a transaction, the first bit sent to the AFE de-

termines the type of transaction, R/W=”1” corre-

sponds to a read transaction while R/W=”0”

corresponds to a write transaction. The next three

bits, address[a2:a0], determine which of the 8 AFE

registers will be accessed (Table 8). This is followed

by the 8-bit data word.

the serially transferred 8-bit word is clocked from the

data source first (the data source being the external

DSP during Write transactions; the STLC1511 during

Read transactions).

The definition of these fields within the 8-bit word is

outlined below in Table 8 and in the detailed register

maps following.

When the voltage on the RESETN pin is low, the bits

in the control register will be reset as per defined in

the detailed register maps.

For a write operation, the data on the DRX pin is

latched into the STLC1511 on the negative edge of

the DIGCLK signal. The data should change state on

the positive edge of the clock.

For a read operation, the data on the DTX pin is out-

put on the positive edge of the clock on pin DIGCLK.

Table 8. AFE Register Map Summary

Addr

[a2:a0]

Name

D7

D6

D5

D4

D3

D2

D1

D0

Type

000

STLC1511 Control 1 (Rx

PGA Gain)

Rx PGA Gain

RW

001

STLC1511 Control 2 (Tx

PGA Gain)

not used

Tx PGA Gain

RW

010

STLC1511 Control 3

(Power Down Reg)

not used

Rx

Opa

mp

Pow

er

Dow

n

not

use

d

Rx

Pow

er

Dow

n

Tx

Pow

er

Dow

n

RW

011

STLC1511 Control 4

(Misc. Control)

not

use

d

DIV Output

(Test mode)

PLL

PFD

inpu

t sel

Tx

Loo

p

back

Clip

Indic

ator

ena

ble

RW

100

AFE Control 5

(PLL Control)

not

use

d

DIG-

REF

Ena

ble

FREF Mode

PLL

Mod

e

Osc

Mod

Clock Source

Control

R/W

101

not used

not used

110

not used

not used

111

AFE Status

not used

Clip

Stat

us

R

<1>Presently there is no difference in the oscillator driver between Oscillator Mode and CPE modes so this bit is unused. However,

it may be required in the future and should be programmed correctly in case needed.