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Motorola MC68340 manual Freescale Semiconductor, Inc Programming

Models: MC68340

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Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

7.4.2 Programming

The basic interface software flowchart required for operation of the serial module is shown in Figure 7-10. The routines are divided into three categories:

•Serial Module Initialization

•I/O Driver

•Interrupt Handling

7.4.2.1SERIAL MODULE INITIALIZATION. The serial module initialization routines consist of SINIT and CHCHK. SINIT is called at system initialization time to check channel A and channel B operation. Before SINIT is called, the calling routine allocates two words on the system stack. Upon return to the calling routine, SINIT passes information on the system stack to reflect the status of the channels. If SINIT finds no errors in either channel A or channel B, the respective receivers and transmitters are enabled. The CHCHK routine performs the actual channel checks as called from the SINIT routine. When called, SINIT places the specified channel in the local loopback mode and checks for the following errors:

•Transmitter Never Ready

•Receiver Never Ready

•Parity Error

•Incorrect Character Received

7.4.2.2I/O DRIVER EXAMPLE. The I/O driver routines consist of INCH, OUTCH, and POUTCH. INCH is the terminal input character routine and gets a character from the channel A receiver and places it in the lower byte of register D0. OUTCH is used to send the character in the lower byte of register D0 to the channel A transmitter. POUTCH sends the character in the lower byte of D0 to the channel B transmitter.

7.4.2.3INTERRUPT HANDLING. The interrupt handling routine consists of SIRQ, which is executed after the serial module generates an interrupt caused by a channel A change- in-break (beginning of a break). SIRQ then clears the interrupt source, waits for the next change-in-break interrupt (end of break), clears the interrupt source again, then returns from exception processing to the system monitor.

7- 40MC68340 USER’S MANUALMOTOROLA

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Motorola MC68340 manual Freescale Semiconductor, Inc Programming
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MC68340 specifications

The Motorola MC68340 is a highly integrated microprocessor that was introduced in the early 1990s. It belongs to the 68000 family of microprocessors and is designed to cater to the demands of embedded systems, particularly in telecommunications and networking applications. This chip represents a significant evolution in microprocessor technology by combining a microprocessor core with additional peripherals on a single chip, making it an attractive solution for engineers looking to design compact and efficient systems.

One of the key features of the MC68340 is its 32-bit architecture, which allows for significant processing power and data handling capabilities. This architecture enables the processor to handle larger data sizes and perform more complex calculations compared to its 16-bit predecessors. The MC68340 operates at clock speeds typically ranging from 16 MHz to 25 MHz. Its dual instruction pipeline enhances throughput, allowing for simultaneous instruction fetches and executions, which significantly boosts performance.

A notable characteristic of the MC68340 is the inclusion of integrated peripherals, which help reduce the overall component count in a system. Key integrated components include a memory management unit (MMU), a direct memory access (DMA) controller, and various communication interfaces such as serial ports. The memory management capabilities enhance the processor's ability to manage memory resources efficiently, enabling it to support multitasking environments commonly found in modern computing.

In terms of connectivity, the MC68340 features connections for both synchronous and asynchronous serial communication, making it well-suited for networking tasks. The processor supports a range of bus standards, including address and data buses, which facilitate seamless interaction with peripheral devices.

Another important aspect of the MC68340 is its flexibility. The processor supports multiple operating modes, including multiple CPU configurations and compatibility with the Motorola 68000 family, allowing for easier integration into existing systems.

Moreover, the MC68340 boasts low power consumption compared to many of its contemporaries, making it an excellent choice for battery-operated applications, enhancing its appeal in sectors like telecommunications, industrial control, and automotive systems. Its combination of performance, integration, versatility, and efficiency has secured the MC68340 a reputable position in the annals of embedded systems technology, proving to be a valuable asset for developers and engineers alike.