PORTS AND CONNECTORS

LCD_PORT

The LCD_PORT interface is connected to the data bus and memory mapped to locations 270

27F hex assigned to CS7. For the standard display, address 270 is the Command register, address 271 is the Data register.

The interface supports all OPTREXä DMC series displays in 8 bit bus mode with up to 80 characters and provides the most common pinout for a dual row rear mounted display connector. Power, ground, and Vee are also available at the LCDPORT-1 connector.

+5V

2

1

GND

A0

4

3

LCD-Vee

LCD1

6

5

/RW

D9

8

7

D8

D11

10

9

D10

D13

12

11

D12

D15

14

13

D14

 

 

 

 

Command Register:$270

Data Register:

$271

LCD-Vee is supplied by U13 and is adjusted by the R18 Potentiometer (adjustable resistor).

See the file KEYLCD12.ASM for an example program using this LCD connector.

LCD3

2

1

 

4

3

LCD2

LCD4

Additional lines can be used as enables for larger panels and are mapped as:

LCD2 = $274 & $275

LCD4 = $27C & $27D

LCD3 = $278 & $279

 

KEYPAD

1PS4

2PS5

3PS6

4PS7

5PP4

6PP5

7PP6

8PP7

The KEYPAD connector is a passive 8-pin connector that can be used to connect a 4 x 4 matrix (16 key) keypad device. The connector is mapped to the HC12 I/O ports S and P. This interface is implemented as a software keyscan. Pins PS4-7 are used as column drivers which are active low outputs. Pins PP4-7 are used for row input and provide an idle hi condition with internal pull-ups to provide active key detection under software control.

See the HC12 Technical Reference Manual for a full description of these pins and the file KEYLCD12.ASM for an example program using this connector.

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Motorola CME-12B/BC, 68HC12BC32, 68HC12B32 manual Ports and Connectors, Lcdport, Keypad, Gnd, LCD3 LCD2 LCD4

68HC12B32, CME-12B/BC, 68HC12BC32 specifications

The Motorola 68HC12BC32, CME-12B/BC, and 68HC12B32 are microcontroller units (MCUs) that are part of the renowned HC12 series, which gained popularity in embedded system designs due to their versatility, robust performance, and comprehensive feature set. These MCUs are widely used in automotive applications, industrial control systems, and various consumer electronics due to their advanced capabilities.

One of the main features of the 68HC12BC32 is its 16-bit architecture, which allows for efficient processing and greater precision in calculations compared to 8-bit counterparts. This feature is crucial for applications requiring high-performance processing, such as real-time control systems. The processor operates at clock speeds of up to 25 MHz, providing the computational power necessary for complex operations.

The 68HC12MCUs include various on-chip memory options, such as ROM, RAM, and EEPROM. For instance, the 68HC12BC32 comes with up to 32 KB of ROM and 1 KB of RAM, along with 512 bytes of EEPROM, making it suitable for applications that require data retention even when the power is turned off. The presence of on-chip memory significantly reduces the need for external components, simplifying system design and enhancing reliability.

Moreover, these microcontrollers feature a rich set of input/output (I/O) capabilities, including multiple general-purpose I/O lines, timer/counter modules, and analog-to-digital converters (ADCs). The integration of these components allows for flexible interfacing with a multitude of sensors and actuators, enabling designers to create sophisticated applications without needing extensive external circuitry.

The embedded communication interfaces, such as SPI (Serial Peripheral Interface), I2C (Inter-Integrated Circuit), and CAN (Controller Area Network), are vital for enabling communication between devices in multiprocessor systems. This capability is particularly beneficial in automotive applications, where seamless data exchange is critical for tasks such as engine control and diagnostics.

Power management features in the 68HC12 series enhance its suitability for battery-powered applications. The ability to enter low-power modes helps extend battery life, making these microcontrollers ideal for portable devices.

In summary, the Motorola 68HC12BC32, CME-12B/BC, and 68HC12B32 microcontrollers are robust and flexible MCUs that offer a combination of advanced processing capabilities, extensive memory options, versatile I/O functionality, and efficient communication interfaces. These characteristics make them well-suited for various applications, from automotive and industrial systems to consumer electronics, ensuring they remain relevant in the evolving landscape of embedded technology.