ADVANCE
CYW43570
10. WLAN MAC and PHY
10.1 IEEE 802.11ac Draft MAC
The CYW43570 WLAN MAC is designed to support high-throughput operation with low-power consumption. It does so without
compromising the Bluetooth coexistence policies, thereby enabling optimal performance over both networks. In addition, several
power saving modes have been implemented that allow the MAC to consume very little power while maintaining network-wide timing
synchronization. The architecture diagram of the MAC is shown in Figure 20.
The following sections provide an overview of the important modules in the MAC.
Figure 20. WLAN MAC Architecture
Embedded CPU Interface
Host Registers, DMA Engines
PSM
UCODE
Memory
TX_FIFO
(32 KB)
RX_FIFO
(10 KB)
PMQ
IFS
PSM
Backoff, BTCX
WEP
TKIP,AES, WAPI
TSF
SHM BUS
NAV
IHR BUS
Shared
Memory
(6 KB)
TXE
TX A-MPDU
RXE
RX A-MPDU
EXT—IHR
MAC—PHY Interface
The CYW43570 WLAN media access controller (MAC) supports features specified in the IEEE 802.11 base standard, and amended
by IEEE 802.11n. The key MAC features include:
■ Enhanced MAC for supporting IEEE 802.11ac Draft features
■ Transmission and reception of aggregated MPDUs (A-MPDU) for high throughput (HT)
■ Support for power management schemes, including WMM power-save, power-save multi-poll (PSMP) and multiphase PSMP
operation
■ Support for immediate ACK and Block-ACK policies
■ Interframe space timing support, including RIFS
■ Support for RTS/CTS and CTS-to-self frame sequences for protecting frame exchanges
■ Back-off counters in hardware for supporting multiple priorities as specified in the WMM specification
■ Timing synchronization function (TSF), network allocation vector (NAV) maintenance, and target beacon transmission time (TBTT)
generation in hardware
■ Hardware offload for AES-CCMP, legacy WPA TKIP, legacy WEP ciphers, WAPI, and support for key management
■ Support for coexistence with Bluetooth and other external radios
■ Programmable independent basic service set (IBSS) or infrastructure basic service set functionality
■ Statistics counters for MIB support
Document Number: 002-15054 Rev. *I
Page 41 of 94
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