BCM43362SKUBGT Datasheet, PDF (37/84 Pages) Cypress Semiconductor – Single-Chip IEEE 802.11™ b/g/n MAC/Baseband/Radio + SDIO

BCM43362 Data Sheet
MAC Features
There are two basic branch instructions: conditional branches and ALU based branches. To better support the
many decision points in the IEEE 802.11 algorithms, branches can depend on either a readily available signals
from the hardware modules (branch condition signals are available to the PSM without polling the IHRs), or on
the results of ALU operations.
WEP
The wired equivalent privacy (WEP) engine encapsulates all the hardware accelerators to perform the
encryption and decryption, as well as MIC computation and verification. The accelerators implement the
following cipher algorithms: legacy WEP, WPA TKIP, WPA2 AES-CCMP.
Based on the frame type and association information, the PSM determines the appropriate cipher algorithm to
be used. It supplies the keys to the hardware engines from an on-chip key table. The WEP interfaces with the
TXE to encrypt and compute the MIC on transmit frames, and the RXE to decrypt and verify the MIC on receive
frames. WAPI is also supported.
TXE
The transmit engine (TXE) constitutes the transmit data path of the MAC. It coordinates the DMA engines to
store the transmit frames in the TXFIFO. It interfaces with WEP module to encrypt frames and transfers the
frames across the MAC-PHY interface at the appropriate time determined by the channel access mechanisms.
The data received from the DMA engines are stored in transmit FIFOs. The MAC supports multiple logical
queues to support traffic streams that have different QoS priority requirements. The PSM uses the channel
access information from the IFS module to schedule a queue from which the next frame is transmitted. Once
the frame is scheduled, the TXE hardware transmits the frame based on a precise timing trigger received from
the IFS module.
The TXE module also contains the hardware that allows the rapid assembly of MPDUs into an A-MPDU for
transmission. The hardware module aggregates the encrypted MPDUs by adding appropriate headers and pad
delimiters as needed.
RXE
The receive engine (RXE) constitutes the receive data path of the MAC. It interfaces with the DMA engine to
drain the received frames from the RXFIFO. It transfers bytes across the MAC-PHY interface and interfaces with
the WEP module to decrypt frames. The decrypted data is stored in the RXFIFO.
The RXE module contains programmable filters that are programmed by the PSM to accept or filter frames
based on several criteria such as receiver address, BSSID, and certain frame types.
The RXE module also contains the hardware required to detect A-MPDUs, parse the headers of the containers,
and disaggregate them into component MPDUS.
Broadcom_®
February 13, 2015 • 43362-DS106-R
IEEE 802.11 b/g/n MAC/Baseband/Radio + SDIO
Page 36
BROADCOM CONFIDENTIAL