HFA3841 Просмотр технического описания (PDF) - Intersil

Номер в каталоге

Компоненты Описание

производитель

HFA3841

Wireless LAN Medium Access Controller

Intersil 

Preliminary - HFA3841

TXC

TX_PE

FIRST DATA BIT SAMPLED

LAST DATA BIT SAMPLED

TXD

TXRDY

LSB DATA PACKET

MSB

DEASSERTED WHEN LAST

CHIP OF MPDU CLEARS

MOD PATH OF 3861

NOTE: Preamble/Header and Data is transmitted LSB first. TXD shown generated from rising edge of TXC.

FIGURE 22. BBP TRANSMIT PORT TIMING

TX_PE

tDI

IOUT, QOUT

TXRDY

TXC

TXD

tPEH

tTCD tTCD

tRC

tTLP

tME

tRI

tTDS

tTDH

FIGURE 23. BBP TRANSMIT PORT SIGNAL TIMING

Power Sequencing

The HFA3841 provides a number of firmware controlled port

pins that are used for controlling the power sequencing and

other functions in the front end components of the PHY.

Packet transmission requires precise control of the radio.

Ideally, energy at the antenna ceases after the last symbol of

information has been transmitted. Additionally, the

transmit/receive switch must be controlled properly to protect

the receiver. It's also important to apply appropriate

modulation to the PA while it's active.

Signaling sequences for the beginning and end of normal

transmissions are illustrated in Figure 24. Table 4 lists

applicable delays.

A transmission begins with PE2 as shown in Figure 24. Next,

the transmit/receive switch is configured for transmission via

the differential pair TR_SW and TR_SW_BAR. This is

followed by TX_PE which activates the transmit state

24

machine in the BBP. Lastly, PA_PE activates the PA. Delays

for these signals related to the initiation of transmission are

referenced to PE2.

Immediately after the final data bit has been clocked out of

the HFA3841, TX_PE is de-asserted. The HFA3841 then

waits for TXRDY to go inactive, signaling that the BBP has

modulated the final information-rich symbol. It then

immediately de-asserts PA_PE followed by placing the

transmit/receive switch in the receive position and ending

with PE2 going high. Delays for these signals related to the

termination of transmission are referenced to the rising edge

of PE2.

Share Link: