AS8202B

TTP-C2NF Communication Controller

www.ams.com

Revision 1.0

1 - 20

1 General Description

The AS8202B communication controller is an integrated device

supporting serial communication according to the TTP specification

version 1.1. It performs all communication tasks such as reception

and transmission of messages in a TTP cluster without interaction of

the host CPU. TTP provides mechanisms that allow the deployment

in high-dependability distributed real-time systems. It provides the

following services:



Predictable transmission of messages with minimal jitter



Fault-tolerant distributed clock synchronization



Consistent membership service with small delay



Masking of single faults

2 Key Features



Dual-channel controller for redundant data transfers



Dedicated controller supporting TTP (time-triggered protocol

class C standardized in SAE 6003)



Suited for dependable distributed real-time systems with

guaranteed response time



Asynchronous data rate up to 4 Mbit/s (MFM/Manchester)



Synchronous data rate 20 to 25 Mbit/s



Bus interface (speed, encoding) for each channel selectable

independently



40 MHz oscillator clock support



16 MHz bus guardian clock with support for 16 MHz crystal or

16 MHz oscillator



Single power supply 3.3V, 0.35µm CMOS process



Full automotive temperature range (-40ºC to 125ºC)



16k x 16 SRAM for message, status, control area

(communication network interface) and for scheduling

information (MEDL)



4k x 16 (plus parity) instruction code RAM for protocol execution

code



Datasheet conforms to protocol revision 2.05



16k x 16 instruction code ROM containing startup execution

code and deprecated protocol code revision 1.00



16-bit non-multiplexed asynchronous host CPU interface



16-bit RISC architecture



Software tools, design support, development boards available



Certification support package according to RTCA/DO-254 DAL



RoHS conform

3 Applications

The device is ideal for application fields such as, aerospace

according to DO-254 level A (e.g. flight control, power distribution,

engine control), industrial systems, and railway systems.

Figure 1. Block Diagram

Bus

Guardi

an

Bus

Guardian

TTP Bus Unit

Synchronous

Bus Interface

(MII)

Asynchronous

Bus Interface

(MFM/

Manchester)

Test Interface

TTP Protocol

Processor Core

Communication

Network

Interface

(CNI)

Instruction Memory

RAM & ROM

D[15:0]

A[11:0]

CEB

OEB

WEB

READYB

INTB

LED[2:0]

RAM_CLK_TESTSE

USE_RAM_CLK

XIN0

RESETB

RxD[1:0]

RxCLK[1:0]

RxDV[1:0]

RxER[1:0]

XIN1

XOUT1

TxD[1:0]

CTS[1:0]

RAM_CLK_TESTSE

FTEST

STEST

FIDIS

TTEST

AS8202B

TxCLK[1:0]