Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

5.1.6 Addressing Modes

Addressing in the CPU32 is register oriented. Most instructions allow the results of the specified operation to be placed either in a register or directly in memory; this flexibility eliminates the need for extra instructions to store register contents in memory.

The seven basic addressing modes are as follows:

Register Direct

Register Indirect

Register Indirect with Index

Program Counter Indirect with Displacement

Program Counter Indirect with Index

Absolute

Immediate

Included in the register indirect addressing modes are the capabilities to postincrement, predecrement, and offset. The PC relative mode also has index and offset capabilities. In addition to these addressing modes, many instructions implicitly specify the use of the SR, SP and/or PC. Addressing is explained fully in the M68000PM/AD, M68000 Family Programmer’s Reference Manual .

5.1.7 Instruction Set

The instruction set of the CPU32 is very similar to that of the MC68020 (see Table 5-1). Two new instructions have been added to facilitate embedded control applications: LPSTOP and table lookup and interpolate (TBL). The following M68020 instructions are not implemented on the CPU32:

BFxxx

— Bit Field Instructions (BFCHG, BFCLR, BFEXTS, BFEXTU,

 

BFFFO, BFINS, BFSET, BFTST)

CALLM, RTM — Call Module, Return Module

CAS, CAS2

— Compare and Set (Read-Modify-Write Instructions)

cpxxx

— Coprocessor Instructions (cpBcc, cpDBcc, cpGEN, cpRESTORE,

 

cpSAVE, cpScc, cpTRAPcc)

PACK, UNPK — Pack, Unpack BCD Instructions

The CPU32 traps on unimplemented instructions or illegal effective addressing modes, allowing user-supplied code to emulate unimplemented capabilities or to define special- purpose functions. However, Motorola reserves the right to use all currently unimplemented instruction operation codes for future M68000 core enhancements.

MOTOROLAMC68340 USER’S MANUAL5- 5

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Motorola MC68340 Freescale Semiconductor, Inc Addressing Modes, Instruction Set, BFFFO, BFINS, BFSET, Bftst, CAS, CAS2

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.