PT0141(06/03)

Ver:0

6

Preliminary Data Sheet

PT8R2401MD 2.4GHz RF Module

|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

Receive Operation In Unidirectional Interface

The primary signal for data reception is RXACTIVE signal. When RXACTIVE goes to high, the RF circuitry starts to operate

and send data after fixed time from RXACTIVE. The baseband receives data and searches for the access code. During receive

mode, DATACLK is sent from PT8R2401 to baseband as a timing reference. The PT8R2401 circuit sends the data to baseband

at the rising edge of DATACLK, where the baseband latches the data at the falling edge of DATACLK. Prior to receiving

information over air, the baseband transfers control information including the hop frequency over the JTAG interfaces, and

enters PT8R2401 into

search access code state

after fixed time to turn on receiver circuitry by driving RXACTIVE HIGH. In

the

search access code state

, the baseband performs all of the tasks required to correlate with the access code from the receive

data. When the baseband has correlated the access code, then it drives SYNCDETECT HIGH and makes PT8R2401 enter into

receive payload state

. During the payload, PT8R2401 eliminates any frequency offset between local and remote Bluetooth

devices based on its measurement during syncword acquisition. PT8R2401 transmits demodulated data to the baseband at half

frequency of DATACLK, which can be read by the baseband using appropriate timing recovery algorithm. The unidirectional

interface is returns to the

idle state

with the baseband driving RXACTIVE LOW after a fixed interval of T

RxOff

.

Figure 4. Receiver procedure timing-diagram in unidirectional interface

Figure 5. Receiver signal timing diagram in unidirectional interface

Idle

VCO Tuning

Search

Access Code

Rx-Burst

Idle

JTAG

Programming

TXACTIVE

TXDATA_EN

TXDATA

RXACTIVE

SYNCDETECT

RXDATA

DATACLK

HOP CMD

Valid Rx Data

t

TuningRX

t

AccessCode

t

RxOn

Rx-On

t

RxOff

DATACLK(13MHz,O)

TXACTIVE(I)

TXDATA_EN(I)

TXDATA(I)

RXACTIVE(I)

SYNCDETECT(I)

RXDATA(O)

PE

SYNC WORD TE

PE : Preamble

TE : Trailer

HEADER+PAYLOAD

t

RxOn

t

RxOff