BCM43362KUBG Datasheet, PDF (36/84 Pages) Cypress Semiconductor – Single-Chip IEEE 802.11™ b/g/n MAC/Baseband/Radio + SDIO

BCM43362 Data Sheet
Figure 17: WLAN MAC Architecture
MAC Features
Embedded CPU Interface
Host Registers, DMA Engines
PMQ
TX-FIFO
32 KB
RX-FIFO
10 KB
PSM
IFS
Backoff, BTCX
TSF
NAV
EXT- IHR
WEP
WEP, TKIP, AES
IHR
BUS
TXE
TX A-MPDU
RXE
RX A-MPDU
SHM
BUS
Shared Memory
6 KB
MAC - PHY Interface
PSM
UCODE
Memory
The following sections provide an overview of the important modules in the MAC.
PSM
The programmable state machine (PSM) is a microcoded engine that provides most of the low-level control to
the hardware to implement the IEEE 802.11 specification. It is a microcontroller that is highly optimized for flow
control operations, which are predominant in implementations of communication protocols. The instruction set
and fundamental operations are simple and general, which allows algorithms to be optimized until very late in
the design process. It also allows for changes to the algorithms to track evolving IEEE 802.11 specifications.
The PSM fetches instructions from the microcode memory. It uses the shared memory to obtain operands for
instructions, as a data store, and to exchange data between both the host and the MAC data pipeline (via the
SHM bus). The PSM also uses a scratchpad memory (similar to a register bank) to store frequently accessed
and temporary variables.
The PSM exercises fine-grained control over the hardware engines by programming internal hardware registers
(IHR). These IHRs are collocated with the hardware functions they control and are accessed by the PSM via
the IHR bus.
The PSM fetches instructions from the microcode memory using an address determined by the program
counter, instruction literal, or a program stack. For ALU operations, the operands are obtained from shared
memory, scratchpad, IHRs, or instruction literals, and the results are written into the shared memory, scratchpad,
or IHRs.
Broadcom_®
February 13, 2015 • 43362-DS106-R
IEEE 802.11 b/g/n MAC/Baseband/Radio + SDIO
Page 35
BROADCOM CONFIDENTIAL