A System-on-Chip Implementation of the IEEE 802.11a MAC Layer

IHPIm Technologiepark 2515236 Frankfurt (Oder)

Germany

IHP Im Technologiepark 25 15236 Frankfurt (Oder) Germany www.ihp-microelectronics.com © 2003 - All rights reserved

A System-on-Chip Implementationof the IEEE 802.11a MAC Layer

Goran Panić, Daniel Dietterle

Zoran Stamenković, Klaus Tittelbach-Helmrich


Overview

• Introduction

• Protocol ImplementationHardware/Software Partitioning

• System ArchitectureComponents Description

• Synthesis Results

Estimated Area & Power

• Layout ResultsFinal Design Results

• Summary

2


Introduction

• Functionality of the MAC described in the IEEE 802.11a standard

• Wireless market

Atheros, Intersil, Cisco, TI, …

• Target: baseband, MAC and radio transcieving part integrated on a single chip

• IHP MAC - designed as a complete solution on chip

• Easy integration with the baseband

3


Design flow overview

Protocoldescription

Performanceinvestigation

Hw Acc design

Architecturedescription

Systemimplementation

SDL model

Simulations &Measurements

VHDLmodel

Logic and Layout Synthesis

Abstract and HDL level

Translation toC model

Hw/Swpartitioning

Systemconsideration

Datapreparation

4


Protocol Implementation

IEEE 802.11System Overview

SingleStation(LanSize)

Testbench

AirLink

RadioChannel

Distribution_system

Config_Generator

LLC_IFMLME_SAP

PLME_SAP

Single_Station

MAC

LLC_handler

OFDM_PHY

Distribution_Channel

Config_Distributor

LLC_IF

MLME_SAP

PHY_SAP

PLME_SAP

MAC_SAP

RadioChannel

SDL Model

• Abstract protocol model

• Generation of C model

• Performance estimation in order to perform Hw/Sw partitioning

5


Hardware Accelerator

CRC

Bus_Interface

Control

PHY_Interface

Tx

CRC

RC4

CRC

Channel_State

Timers MIB

Rx

Processor bus

On-chip RAM Baseband processor

• executes timing critical MAC functions

• Timers, CRC, RC4, address filter

• reduction of power consumption

• interface between baseband and CPU

• completely modeled in VHDL

• synthesized and simulated for 80MHz

• 5x512B single-port memory

• 2x256B dual-port memory

• soft resetable

6


System Architecture

MIPS 4KEpCore

Peripheral BusController

EC-to-X BusController

I2C

HwAcc

UART 0

SRAM FLASH

Serial 0

Serial 1

I2C

EPP

GPIO

EJTAG

UART 1

GPIO

• complete rtl description in VHDL/Verilog• verification environment and synthesis scripts

EC

X#0

X#1

7


System Architecture

MIPS 4KEpCore

Peripheral BusController

EC-to-X BusController

I2C

HwAcc

UART 0

Async RAM Async ROM

Serial 0

Serial 1

I2C

EPP

GPIO

EJTAG

UART 1

GPIO

• complete rtl description in VHDL/Verilog• verification environment and synthesis scripts

EC

X#0

X#1

Test program

TestEnvironment

Componentsverification

models

8


Synthesis Results

Design nameEstimatedarea (%)

Estimatedpower(%)

MIPS core 16.7 17

I 2C bus controller 0.3 0.4

UART x 2 3.5

EC-to-X bus controller 3.4 0.8

Peripheral buscontroller

0.8 1.6

Accelerator core 14.1 15.9

Single-port RAM 512B x 5 41.6 49.7

Dual-port RAM 256B x 2 19.4 9.5

GPIO 0.8 1.3

Glue logic 0.2 0.3

Chip 100 100

9

2.7


System Layout

Facts• Technology: IHP 0.25μm CMOS

• Area: ~ 30 mm2

• Number of gates: 420,000 NAND

• Number of pins: 140 sig + 16 pow

• Package: PQFP 208L 28*28*3.35P0.5 • Peak Power: ~1W at 80 MHz, 2.5V

• Chip testing:

Successful on Agilent 93000

10


Summary

Presented design flow provides:

• Efficient and flexible modeling and implementation of a MAC protocol

• Low power

• High performance

• Easy integration to a baseband processing unit

What can be done in the future:

• PCMCIA interface to TCP/IP layer (rev 1)

• Custom connection to the baseband (rev 1)

• Usage of high performance memory blocks (rev 1)

• Clock gating

• AMBA bus

11

Documents

A System-on-Chip Implementation of the IEEE 802.11a MAC Layer