8-bit MCU speeds LIN bus development in new cars

Motorola’s Semiconductor Product Sector, a founding member of the Local Interconnect Network Consortium, has expanded its 8-bit HC08 ‘Q-LIN’ family with a LIN-slave device, the 68HC908QL4.

Motorola’s Semiconductor Product Sector, a founding member of the LIN (Local Interconnect Network) Consortium, has expanded its 8-bit HC08 ‘Q-LIN’ family with a LIN-slave device, the 68HC908QL4.

The QL4 is said to help enable rapid design of automotive extras, such as power window lift motors and side-view mirrors, which are connected to the LIN bus for control. Wiring to switches, actuators, lamps and motors can then be minimised, resulting in lower overall vehicle weight.

According to a statement, LIN is a cost effective serial communication system for distributed electronic systems in vehicles and the QL4 is Motorola’s first microcontroller (MCU) to offer fully automatic LIN slave functionality.

The flash-based QL4 is engineered to support the LIN bus operation at full LIN bus communication speed (20 kbps). This automation enables the QL4 to find and communicate to LIN messages at virtually any speed using its advanced automatic synchronisation and baud features.

This plug-and-play flexibility allows an automotive designer to easily utilise the QL4 MCU in the LIN bus environment without any code changes. The QL4 also supports high-speed communications for rapid in-circuit programming.

No LIN bus synchronisation code is needed in the QL4 software and no trimming of the internal oscillator is required to communicate. The QL4 also offers exceptional performance by helping to reduce system interrupts by more than 80% over UART solutions. It also has the smallest driver code required to process LIN messages.

Like existing ‘Q’ HC08 devices, the QL4 incorporates 4 KB of flash, with ROM-based options planned for later introduction. Other standard features include an integrated internal oscillator that helps save money and space by virtually eliminating the need for external components, a computer operating properly (COP) watchdog, low voltage interrupt (LVI), keyboard interrupt (KBI), LED drive capability and a 6-channel 10-bit analogue to digital (A/D) converter.

Samples of the 68HC908QL4 are available today with production quantities expected in 2004. Suggested resale pricing for the MC68HC908QL4 (4 KB flash, 16-pin package) in one million-piece quantities and above is expected to be less than $1.00.

On the web