About the Motorola MC 68HC11

Back to architecture To the MC68HC11 family

Onboard subsystems

The M68HC11 Family leads in microcontroller memory technology. In fact, the 68HC711E9 was the first device to integrate EPROM and EEPROM technologies on the same chip. In many applications, the M68HC11 provides a single chip solution with mask programmed ROM or user-programmable EPROM.

The M68HC11 Family's RAM uses a fully static design, and the contents can be preserved during periods of processor inactivity.

One Time Programmable (OTP) and windowed EPROM versions of M68HC11 devices are offered across the family providing a cost effective, user-programmable ROM facility for small volume prototypes and development runs. Secure EPROM devices are also available for applications where code is at risk of being compromised.

The M68HC11's EEPROM is ideal for the secure storage of essential calibration, diagnostic and security information.

A 4 channel Direct Memory Access (DMA) unit on some devices permits fast data transfer between two blocks of memory (including externally mapped memory in expanded mode), between registers or between registers and memory.

The industry standard M68HC11 timer provides flexibility, performance and ease of use. The system is based on a free-running 16-bit counter with a programmable prescaler, overflow interrupt, and separate function interrupts.
Additional M68HC11 timer features include:

It also provides a selection of timer sub systems geared towards timing-intensive applications; each supported by additional features associated with specific family members, including:

A/D Convertor
A/D systems are available with 8 to 12 channels and 8 and 10 bit resolution. The A/D is software programmable to provide single or continuous conversion modes. The M68HC11 Family now also offers D/A conversion for added versatility.

Serial Communications Interface (SCI)
The SCI features a full duplex Universal Asynchronous Receiver/ Transmitter system, using the non-return-to zero (NRZ) format for microcontroller-to-PC connections, or to form a serial communications network connecting several widely distributed microcontrollers. Through the SCI, the built-in bootstrap interface allows in-circuit programming, and facilitates diagnostic and test operation of your application.
Data format - 1 Start, 8 or 9 data, and one stop bit.
Data rate - 150 - 312500 Baud (312500 is using 4 MHz E clock)

Serial Peripheral Interface (SPI)
The SPI is capable of inter-processor communication in a - _ multiple master system. Synchronous serial communications, comprises CLK, DATA IN, DATA OUT and optionally chip selects. As well as using specific SPI devices, it is very easy to expand I/O using the SPI and standard logic devices (e.g. 74HC595 and 74HC165). The SPI also enables synchronous communication between the microcontroller and peripheral, devices such as:

Pulse Width Modulation
The M68HC11 Family offers a selection of Pulse Width Modulation (PWM) options to support a variety of applications. Up to six PWM channels can be selected to create continuous waveforms with programmable rates and software selectable duty cycles from 0 to 100%.

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