RF3000 データシートの表示（PDF） - RF Micro Devices

部品番号

コンポーネント説明

一致するリスト

RF3000

SPREAD-SPECTRUM BASEBAND MODEM

RF Micro Devices 

RF3000

RF3000 Method of Operation

The transmitter power enable (TX PE) input enables the transmitter process. (Note: Transmit has priority over receive.)

When TX PE is high, the LNA GS signal will be driven low. The TX RDY output indicates the readiness of the RF3000 to

receive data for transmit. Transmitted data is passed into the RF3000 through the TXDATA input and clocked by the

DATA CLK output. The receiver power enable (RX PE) input enables the receiver, and the receive data ready (RX RDY)

signal indicates that received data is upcoming. The RF3000 generates the received data clocks, and outputs the

received data, through the RX DATA output. The receiver port also provides a clear channel assessment (CCA) to the

MAC.

The table below summarizes the operation of the chip. The user should note that RX PE must be High to perform CCA.

TX PE

0

0

1

1

RX PE

0

1

0

1

Operation

Standby mode.

RX is powered up. CCA circuity is active.

TX is powered up. Begin TX. CCA is inactive.

RESERVED

IEEE802.11b Transmit Modes

IEEE802.11b DSSS Transmit Modes

The RF3000 supports PSK and CCK DSSS modes defined in IEEE802.11b specification. The RF3000 also supports the

optional short preamble and header format as defined in IEEE802.11b.

The following section describes IEEE802.11b DSSS data transmission. The user must first prepare the applicable con-

trol port registers to determine the mode of operation and the transmission length. The mode of operation must be writ-

ten into Register 1, followed by setting the transmission length (in microseconds). The length is to be written into

Registers 17 (bit 0 only), 18 and 19. Mode byte values for IEEE802.11b modes are summarized below.

IEEE802.11 DSSS Mode

1Mbps DBPSK

2Mbps DQPSK Long preamble

2Mbps DQPSK Short preamble

5.5Mbps CCK Long preamble

5.5Mbps CCK Short preamble

11Mbps CCK Long preamble

11Mbps CCK Short preamble

Mode Byte Value

0 x 0016

0 x 2016

0 x 3016

0 x 4016

0 x 5016

0 x 6016

0 x 7016

Once the control port values are written, the RF3000 is ready to transmit data. Optionally, the TX length value can be

written during the 128µS of preamble. When the user is ready to transmit, TX PE is driven High. This signals the RF3000

to assemble and transmit the 802.11 preamble and header, as described below.

Preamble

128 1’s

SFD

(16-bits)

Service

(8-bits)

Header

Signal

(8-bits)

Length

(16-bits)

CRC

(16-bits)

Data

Data

(x-bits)

The preamble and header for 1Mbps mode is always transmitted as 1Mbps BPSK. However for 2Mbps, 5.5Mbps and

11Mbps modes, IEEE802.11b allows a short preamble, which has the preamble, transmitted as 1Mbps BPSK and the

header transmitted as 2Mbps QPSK. The usage of the optional short preamble is selected when the transmission mode

is written to the control port.

Rev A4 031216

11-331

Share Link: