ADVANCE
CYW43143
on the frame type, transmission rules in the IEEE 802.11™ protocol, and the current medium occupancy scenario. After the trans-
mission completes, a TX status is returned to the host, informing the host of the transmission.
The MAC contains a 10 KB RX FIFO. Received frames are sent to the host along with RX descriptors that contain additional frame
reception information.
The power management block maintains power management state information of the core (and of the associated STAs in the case
of an AP) to help with dynamic frame transmission decisions by the core.
The wireless security engine performs the required encryption/decryption on the TX/RX frames. This block supports separate transmit
and receive keys with four shared keys and 50 link-specific keys. The link-specific keys are used to establish a secure link between
any two network nodes. The wireless security engine supports the following encryption schemes that can be selected on a per-
destination basis:
■ None: The wireless security engine acts as a pass-through
■ WEP: 40-bit secure key and 24-bit IV as defined in IEEE Std. 802.11-2007
■ WEP128: 104-bit secure key and 24-bit IV
■ TKIP: IEEE Std. 802.11-2007
■ AES: IEEE Std. 802.11-2007
The transmit engine is responsible for the byte flow from the TX FIFO to the PHY interface through the encryption engine and the
addition of a CRC-32 Frame Check Sequence (FCS) as required by IEEE 802.11-2007. Similarly, the receive engine is responsible
for byte flow from the PHY interface to the RX FIFO through the decryption engine and for detection of errors in the RX frame.
The timing block performs the TSF, NAV, and IFS functionality as described in IEEE Std. 802.11-2007.
The Programmable State Machine (PSM) coordinates the operation of different hardware blocks required for both transmission and
reception. The PSM also maintains the statistics counters required for MIB support.
6.2 IEEE 802.11n PHY Description
The PHY supports:
■ Programmable data rates from MCS 0–7 in 20 MHz and 40 MHz channels, as specified in 802.11n.
■ Short Guard Interval (SGI) and optional reception of two space-time block encoded streams.
■ All scrambling, encoding, forward error correction, and modulation in the transmit direction, and inverse operations in the receive
direction.
■ Advanced digital signal processing technology for best-in-class receive sensitivity.
■ Both mixed-mode and optional greenfield preamble of 802.11n.
■ Both long and optional short IEEE 802.11b preambles.
■ Closed-Loop transmit power control.
■ Per-packet receive antenna diversity.
■ Automatic Gain Control (AGC).
■ Available per-packet channel quality and signal strength measurements.
The CYW43143 PHY provides baseband processing at all mandatory 802.11n data rates up to 150 Mbps, and the legacy rates
specified in IEEE 802.11b/g, including 1, 2, 5.5, 6, 9, 11, 12, 18, 24, 36, 48, and 54 Mbps. This core acts as an intermediary between
the MAC and the 2.4 GHz radio, converting back and forth between packets and baseband waveforms.
Document Number: 002-15045 Rev. *F
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