GENERAL DESCRIPTION

The MSM6636B is a transmission controller for automotive LAN based on data communication protocol SAE-J1850. This device can realize a data bus topology bus LAN system with a PWM bit encoding method (41.6 kbps). In addition to a protocol control circuit, MSM6636B has an enclosed quartz oscillation circuit, host CPU interface (parallel interface), a transmit/receive buffer, and a bus receiver circuit that decreases the burden on the host CPU.

FEATURES

• Based on SAE-J1850 CLASS B DATA COMMUNICATION NETWORK INTERFACE (issued August 12, 1991)

• Non-destructive collision and priority control using CSMA/CD

• Internal transmit buffer (1 frame) and receive buffer (2 frames)

• Modulating/demodulating: PWM (Pulse Width Modulation)

• Transmission speed: 41.6 kbps

• Multi-address setting with physical addressing: 1 type / functional addressing: 15 types

• Address filter function by multi-addressing (broadcasting possible)

• Automatic retransmission function by arbitration loss and non ACK

• Three types of in-frame response support:

① Single-byte response from a single node

② Multi-byte response from a single node (with CRC code)

③ Single-byte response from multiple nodes (ID response as ACK)

• Error detection by cyclic redundancy check (CRC)

• Various communication error detections

• Dual-wire bus abnormality detection by internal bus receiver and fault tolerance function

• Host CPU interface is accessed in parallel

• Sleep function

Low current consumption mode by oscillation stop (IDS Max < 50µA)

SLEEP / WAKE UP control from host CPU, WAKE UP via LAN bus

• Package: 24-pin plastic SOP (SOP24-P-430-1.27-K) (Product name : MSM6636BGS-K)