4-
1
HFA3860
11 Mbps Direct Sequence Spread
Spectrum Baseband Processor
The Intersil HFA3860 Direct Sequence
(DSSS) baseband processor is part of
the PRISM 2.4GHz radio chipset, and
contains all the functions necessary for
a full or half duplex packet baseband
transceiver for applications requiring 11 Mbps performance.
The HFA3860 has on-board A/Ds for analog I and Q inputs, for
which the HFA3726 IF QMODEM is recommended. Differential
phase shift keying modulation schemes DBPSK and DQPSK,
with data scrambling capability are available, along with M-Ary
Bi-Orthogonal Keying to provide a variety of data rates. Built-in
flexibility allows the HFA3860 to be configured through a
general purpose control bus, for a range of applications. A
Receive Signal Strength Indicator (RSSI) monitoring function
with on-board 6-bit A/D provides Clear Channel Assessment
(CCA) to avoid data collisions and optimize network throughput.
The HFA3860 is housed in a thin plastic quad flat package
(TQFP) suitable for PCMCIA board applications.
Simplified Block Diagram
Features
Complete DSSS Baseband Processor
Processing Gain . . . . . . . . . . . . . . . . . . . . . . . . . .
10.4dB
Programmable Data Rate. . . . . . . . 1, 2, 5.5, and 11 Mbps
Ultra Small Package . . . . . . . . . . . . . . . . . . . . 7 x 7 x 1mm
Single Supply Operation (44MHz Max) . . . . . 2.7V to 3.6V
Modulation Methods . . . . . . .DBPSK, DQPSK, and MBOK
Supports Full or Half Duplex Operations
On-Chip A/D Converters for I/Q Data (3-Bit, 22 MSPS)
and RSSI (6-Bit)
Similar Pinout to HFA3824
Applications
Systems Targeting IEEE 802.11 WLAN Standard
Point-to-Point Links
DSSS PCMCIA Wireless Transceiver
Spread Spectrum WLAN RF Modems
TDMA Packet Protocol Radios
Part 15 Compliant Radio Links
Portable Bar Code Scanners/POS Terminal
Portable PDA/Notebook Computer
Wireless Digital Audio
Wireless Digital Video
PCN/Wireless PBX
Pinout
HFA3860 (TQFP)
Ordering Information
PART NO.
TEMP.
RANGE (
o
C)
PKG. TYPE
PKG. NO.
HFA3860IV
-40 to 85
48 Ld TQFP
Q48.7x7
HFA3860IV96
-40 to 85
Tape and Reel
TM
RSSI
I
IN
Q
IN
I
OUT
Q
OUT
DEMOD.
PRO-
CESSOR
MOD.
D
A
T
A
T
O
NETW
ORK
CTRL
PR
OCESSOR
6-BIT
A/D
3-BIT
A/D
3-BIT
A/D
CCA
SPREADER
DE-SPREADER
INTER-
FACE
1
2
3
4
5
6
7
8
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
9
10
11
12
13 14 15 16
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
RXCLK
RXD
MD_RD
RX_PE
CCA
GND
MCLK
V
DD
RESET
ANTSE
ANTSE
SD
EST_CK
TX_PE
TXD
TXCLK
TX_RDY
R/W
CS
V
DDA
GND
I
IN
GND
V
DD
I
OUT
Q
OUT
TEST7
TEST6
TEST5
V
DD
GND
TEST3
TEST2
TEST1
TEST0
TEST4
Q
IN
RSSI
GND
V
REFP
V
REFN
V
DD
A
GND
V
DD
A
V
DD
GND
SDI
SCLK
Data Sheet
July 1998
File Number
4347
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
http://www.intersil.com or 407-727-9207
|
Copyright
Intersil Corporation 1999
PRISM is a registered trademark of Intersil Corporation. PRISM logo is a trademark of Intersil Corporation.
4-
2
Table of Contents
PAGE
Simplified Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
Typical Application Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
External Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
Control Port (4 Wire) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
TX Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
RX Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
I/Q A/D Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
A/D Calibration Circuit and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
RSSI A/D Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Test Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Power Down Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Transmitter Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Header/Packet Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Scrambler and Data Encoder Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Spread Spectrum Modulator Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
Clear Channel Assessment (CCA) and Energy Detect (ED) Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Demodulator Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Acquisition Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
PN Correlators Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Data Demodulation and Tracking Description (DBPSK and DQPSK Modes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Data Decoder and Descrambler Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Data Demodulation and Tracking Description (BMBOK and QMBOK Modes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Demodulator Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
A Default Register Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Test Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Typical Application Diagram
For additional information on the PRISMTM chip set, call
(407) 724-7800 to access Intersil' AnswerFAX system. When
prompted, key in the four-digit document number (File #) of
the data sheets you wish to receive.
The four-digit file numbers are shown in the Typical
Application Diagram, and correspond to the appropriate
circuit.
HFA3860
4-
3
QUAD IF MODULATOR
RFPA
HFA3925
HFA3726
DSSS BASEBAND PROCESSOR
D
A
T
A
T
O
MA
C
CTRL
HFA3860
HFA3524
0
o
/90
o
VCO
A/D
A/D
MAC-PHY
INTERFACE
802.11
VCO
DUAL SYNTHESIZER
HFA3624
UP/DOWN
CONVERTER
A/D
(FILE# 4067)
(FILE# 4347)
(FILE# 4062)
(FILE# 4066)
(FILE# 4132)
M
U
X
M
U
X
DEMOD
MOD.
DE-
SPREAD
SPREAD
Q
I
HFA3424
(NOTE)
(FILE# 4131)
TYPICAL TRANSCEIVER APPLICATION CIRCUIT USING THE HFA3860
NOTE: Required for systems targeting 802.11 specifications.
CCA
RXI
RXQ
RSSI
TXI
TXQ
2
Pin Descriptions
NAME
PIN
TYPE I/O
DESCRIPTION
V
DDA
(Analog)
10, 18, 20
Power
DC power supply 2.7V - 3.6V (Not Hardwired Together On Chip).
V
DD
(Digital)
7, 21, 29, 42
Power
DC power supply 2.7 - 3.6V
GND
(Analog)
11, 15, 19
Ground
DC power supply 2.7 - 3.6V, ground (Not Hardwired Together On Chip).
GND
(Digital)
6, 22, 31, 41
Ground
DC power supply 2.7 - 3.6V, ground.
V
REFN
17
I
"Negative" voltage reference for A/D's (I and Q) [Relative to V
REFP
]
V
REFP
16
I
"Positive" voltage reference for A/D's (I, Q and RSSI)
I
IN
12
I
Analog input to the internal 3-bit A/D of the In-phase received data.
Q
IN
13
I
Analog input to the internal 3-bit A/D of the Quadrature received data.
ANTSEL
26
O
The antenna select signal changes state as the receiver switches from antenna to antenna during the
acquisition process in the antenna diversity mode. This is a complement for ANTSEL (pin 27) for
differential drive of antenna switches.
ANTSEL
27
O
The antenna select signal changes state as the receiver switches from antenna to antenna during the
acquisition process in the antenna diversity mode. This is a complement for ANTSEL (pin 26) for
differential drive of antenna switches.
RSSI
14
I
Receive Signal Strength Indicator Analog input.
HFA3860
4-
4
TX_PE
2
I
When active, the transmitter is configured to be operational, otherwise the transmitter is in standby
mode. TX_PE is an input from the external Media Access Controller (MAC) or network processor to
the HFA3860. The rising edge of TX_PE will start the internal transmit state machine and the falling
edge will initiate shut down of the state machine. TX_PE envelopes the transmit data except for the last
bit. The transmitter will continue to run for 3 symbols after TX_PE goes inactive to allow the PA to shut
down gracefully.
TXD
3
I
TXD is an input, used to transfer MAC Payload Data Unit (MPDU) data from the MAC or network
processor to the HFA3860. The data is received serially with the LSB first. The data is clocked in the
HFA3860 at the rising edge of TXCLK.
TXCLK
4
O
TXCLK is a clock output used to receive the data on the TXD from the MAC or network processor to
the HFA3860, synchronously. Transmit data on the TXD bus is clocked into the HFA3860 on the rising
edge. The clocking edge is also programmable to be on either phase of the clock. The rate of the clock
will be dependent upon the data rate that is programmed in the signalling field of the header.
TX_RDY
5
O
TX_RDY is an output to the external network processor indicating that Preamble and Header
information has been generated and that the HFA3860 is ready to receive the data packet from the
network processor over the TXD serial bus. The TX_RDY returns to the inactive state when the last
chip of the last symbol has been output.
CCA
32
O
Clear Channel Assessment (CCA) is an output used to signal that the channel is clear to transmit. The
CCA algorithm makes its decision as a function of RSSI, Energy Detect (ED), and Carrier Sense
(CRS). The CCA algorithm and its features are described elsewhere in the data sheet.
Logic 0 = Channel is clear to transmit.
Logic 1 = Channel is NOT clear to transmit (busy).
This polarity is programmable and can be inverted.
RXD
35
O
RXD is an output to the external network processor transferring demodulated Header information and
data in a serial format. The data is sent serially with the LSB first. The data is frame aligned with
MD_RDY.
RXCLK
36
O
RXCLK is the bit clock output. This clock is used to transfer Header information and payload data
through the RXD serial bus to the network processor. This clock reflects the bit rate in use. RXCLK is
held to a logic "0" state during the CRC16 reception. RXCLK becomes active after the SFD has been
detected. Data should be sampled on the rising edge. This polarity is programmable and can be
inverted.
MD_RDY
34
O
MD_RDY is an output signal to the network processor, indicating header data and a data packet are
ready to be transferred to the processor. MD_RDY is an active high signal and it envelopes the data
transfer over the RXD serial bus. MD_RDY goes active when the SFD is detected and returns to its
inactive state when RX_PE goes inactive or an error is detected in the header.
RX_PE
33
I
When active, the receiver is configured to be operational, otherwise the receiver is in standby mode.
This is an active high input signal. In standby, RX_PE inactive, all A/D converters are disabled.
SD
25
I/O
SD is a serial bi-directional data bus which is used to transfer address and data to/from the internal
registers. The bit ordering of an 8-bit word is MSB first. The first 8 bits during transfers indicate the
register address immediately followed by 8 more bits representing the data that needs to be written or
read at that register.
SCLK
24
I
SCLK is the clock for the SD serial bus.The data on SD is clocked at the rising edge. SCLK is an input
clock and it is asynchronous to the internal master clock (MCLK)The maximum rate of this clock is
11MHz or one half the master clock frequency, whichever is lower.
SDI
23
I
This pin is not used in the 4 wire interface described in this data sheet. It should not be left floating.
R/W
8
I
R/W is an input to the HFA3860 used to change the direction of the SD bus when reading or writing
data on the SD bus. R/W also enables the serial shift register used in a read cycle. R/W must be set
up prior to the rising edge of SCLK. A high level indicates read while a low level is a write.
CS
9
I
CS is a Chip select for the device to activate the serial control port.The CS doesn't impact any of the
other interface ports and signals, i.e., the TX or RX ports and interface signals. This is an active low
signal. When inactive SD, SCLK, and R/W become "don't care" signals.
TEST 7:0
37, 38, 39,
40, 43, 44,
45, 46
O
This is a data port that can be programmed to bring out internal signals or data for monitoring. These
bits are primarily reserved by the manufacturer for testing. A further description of the test port is given
at the appropriate section of this data sheet.
Pin Descriptions
(Continued)
NAME
PIN
TYPE I/O
DESCRIPTION
HFA3860
4-
5
External Interfaces
There are three primary digital interface ports for the
HFA3860 that are used for configuration and during normal
operation of the device as shown in Figure 1. These ports
are:
The Control Port, which is used to configure, write and/or
read the status of the internal HFA3860 registers.
The TX Port, which is used to accept the data that needs
to be transmitted from the network processor.
The RX Port, which is used to output the received
demodulated data to the network processor.
In addition to these primary digital interfaces the device
includes a byte wide parallel Test Port which can be
configured to output various internal signals and/or data.
The device can also be set into various power consumption
modes by external control. The HFA3860 contains three
Analog to Digital (A/D) converters. The analog interfaces to
the HFA3860 include, the In phase (I) and quadrature (Q)
data component inputs, and the RF signal strength indicator
input. A reference voltage divider is also required external to
the device.
Control Port (4 Wire)
The serial control port is used to serially write and read data
to/from the device. This serial port can operate up to a
11MHz rate or 1/2 the maximum master clock rate of the
device, MCLK (whichever is lower). MCLK must be running
during programming. This port is used to program and to
read all internal registers. The first 8 bits always represent
the address followed immediately by the 8 data bits for that
register. The two LSBs of address are don't care, but
reserved for future expansion. The serial transfers are
accomplished through the serial data pin (SD). SD is a
bidirectional serial data bus. Chip Select (CS), and
Read/Write (R/W) are also required as handshake signals
for this port. The clock used in conjunction with the address
and data on SD is SCLK. This clock is provided by the
external source and it is an input to the HFA3860. The timing
relationships of these signals are illustrated in Figures 2 and
3. R/W is high when data is to be read, and low when it is to
be written. CS is an asynchronous reset to the state
machine. CS must be active (low) during the entire data
transfer cycle. CS selects the serial control port device only.
The serial control port operates asynchronously from the TX
and RX ports and it can accomplish data transfers
independent of the activity at the other digital or analog
ports.
The HFA3860 has 32 internal registers that can be accessed
through the control port. These registers are listed in the
Configuration and Control Internal Register table. Table 1 lists
the configuration register number, a brief name describing the
register, and the HEX address to access each of the registers.
The type indicates whether the corresponding register is
Read only (R) or Read/Write (R/W). Some registers are two
bytes wide as indicated on the table (high and low bytes).
See Tech Brief #360 on timing issues between the serial
clock (SCLK) and the chip master clock (MCLK).
TEST_CK
1
O
This is the clock that is used in conjunction with the data that is being output from the test bus (TEST
0-7).
RESET
28
I
Master reset for device. When active TX and RX functions are disabled. If RESET is kept low the
HFA3860 goes into the power standby mode. RESET does not alter any of the configuration register
values nor does it preset any of the registers into default values. Device requires programming upon
power-up. After RESET is de-activated, RX_PE must be activated for at least 2 MCLKs before RX and
TX functions are restored.
MCLK
30
I
Master Clock for device. The nominal frequency of this clock is 44MHz. This is used internally to
generate all other internal necessary clocks and is divided by 2 or 4 for the transceiver clocks.
I
OUT
48
O
TX Spread baseband I digital output data. Data is output at the chip rate.
Q
OUT
47
O
TX Spread baseband Q digital output data. Data is output at the chip rate.
NOTE: Total of 48 pins; ALL pins are used.
Pin Descriptions
(Continued)
NAME
PIN
TYPE I/O
DESCRIPTION
TXD
TXCLK
TX_RDY
RXD
RXC
MD_RDY
CS
SD
SCLK
R/W
SDI
I (ANALOG)
Q (ANALOG)
RSSI (ANALOG)
V
REFN
V
REFP
TX_PE
RX_PE
RESET
TEST
TX_PORT
RX_PORT
CONTROL_PORT
ANALOG
INPUTS
A/D
REFERENCE
POWER
DOWN
SIGNALS
TEST
PORT
8
HFA3860
FIGURE 1. EXTERNAL INTERFACE
ANTSEL
HFA3860
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