CONFIG SWITCH

The CME-12B/BC board is shipped from the manufacturer with the following default CONFIG SWITCH settings:

1

2

3

4

5

6

7

8

ON

ON

ON

ON

OFF

ON

OFF

OFF

The 8 position CONFIG SWITCH provides an easy method of configuring the CME-12B/BC32 board operation. Following are the configuration switch descriptions and HC12 I/O port usage:

CONFIG

OPERATION when in ON position

HC12 I/O PORT USED

SWITCH

 

 

 

 

 

 

 

1

MODE

A

selection

(see

Mode

chart

MODA / PE5

below)

 

 

 

 

 

 

 

 

 

 

 

 

2

MODE

B

selection

(see

Mode

chart

MODB / PE6

below)

 

 

 

 

 

 

 

 

 

 

 

 

3

EXT –External Memory enable (1)

 

N/A

4

MON –Monitor Memory enable (2)

 

N/A

5

VPP - Flash VPP voltage enable

 

N/A

6

RXD - Serial Port RXD input enable

 

PS0 / RXD

7

PC0 –CAN Port RXCAN enable

 

PC0

8

PC1 –CAN Port TX enable

 

 

PC2

(1)Enables memory bus operation for access to board memory. Expanded bus must be on for proper operation.

(2)Enables monitor EPROM’s in memory map at 0x8000 – FFFF hex if CONFIG SWITCH position 3 is also on. When in off position memory space is SRAM for BDM use.

MODE CHART

Single Chip Mode

A and B = OFF

Expanded Wide Mode

A and B = ON

MEM-SEL JUMPERS

Memory sockets U4/5 are shipped with 32K byte RAM devices. U6/7 are shipped with 32K byte EPROM devices programmed with the D-bug12 monitor.

1,3,4

IN: enables RAM or EEPROM, 32K devices to U6/7

1,3

IN: enables RAM or EEPROM, 8K devices in U6/7

2,4

IN: enables EPROM, 8K or 32K devices in U6/7 (Default)

10

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Motorola 68HC12B32, 68HC12BC32, CME-12B/BC manual Config Switch, MEM-SEL Jumpers

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.