ISM 868 MHz, 433 MHz and 315 MHz FSK Receiver Cell – Preliminary Data Sheet

ASCell3912

Rev. A, February 2000

Page 6 of 14

Austria Mikro Systeme International AG

µC-readout

WAKE_UP

Receiver-sleep-time =

(STR +1) * 20 ms

SYNC

13.80ms

DATA

12.28ms

SYNC

13.80ms

DATA

12.28ms

SYNC

13.80ms

DATA

12.28ms

SYNC

13.80ms

DATA

12.28ms

Receiver Wake up sequence

max. 22.25ms

XO-

Set

Wake-Up

trigger

Wake up

RX

start

detection

TX-Start

Wake-Up

trigger

TX- stop

RX-sleep

Data reception and store data

XO-

Set

SYNC

13.80m

s

DATA

Data reception

RX-

Status

TX-

Status

data detection

completed

≤30ms

RE_INT

≤0.5ms

RX

DR

Internal flags:

r

Detection with 0 GSM-interferer

r

r

Detection with 2 GSM interferer

r

Active time after last useful data

≤30ms

r

Cristal Oscillator setup-time

µC_CLK

Figure 2:

ASCell3912 basic timing.

1.2.3 Receiver Configuration

The configuration register can be loaded from a µC via the serial interface. The Table 2 below

shows the contents of the configuration register. Bit b0 is the first transmitted bit. The setup

contains the LNA set, frequency band and the sleep time interval of the receiver.

bit #

Name

Description

Configuration

Comments

0

LNA

LNA gain switch

L= LNA Gain is high

H= LNA Gain is -10dB

default

[1..2]

FB[1:0]

Frequency band select with

FB1 is MSB

L, L (FB1, FB0) = 868.3 MHz

L, H = 433.92 MHz

H, L = 315 MHz

H, H = not used

default

[3..8]

STR[5:0]

Sleep time interval set of

the receiver, with STR5 is

MSB

Note: for STR = 00h the

witing period between

two consecutive wake-

up cycles will be 148 bit.

Table 2: Format of the configuration Register