Addressing Modes, Opcode, Next a | Texas Instruments MSP50C614

Instruction Syntax and Addressing Modes

4.3.2Addressing Modes

The addressing modes on the MSP50P614/MSP50C614 are immediate, di- rect, indirect with post modification, and three relative modes. The relative modes are:

- Relative to the INDEX or R5 register. The effective address is (indirect reg- ister + INDEX).

-Short relative to the PAGE or R6 register. The effective address is (PAGE+7 bit positive offset).

-Long relative to Rx. The effective address is (indirect register Rx + 16 bit positive offset).

When string instructions are executed, the operation of the addressing mode used is modified. For all addressing modes except indirect with post modifica- tion, a temporary copy of the memory address is used to fetch the least signifi- cant data word of the string. Over the next n instruction cycles, the temporary copy of the address is auto-incremented to fetch the next n words of the string. Since the modification of the address is temporary, all Rx registers are un- changed and still have reference to the least significant data word in memory. String data fetches using the indirect with post modification addressing mode and writes the modified address back to the indirect register at each cycle of the string. This will leave the address in the Rx register pointing to the data word whose address is one beyond the most significant word of the string.

All addressing modes except immediate addressing are encoded in bits 0 to 7 of the instruction's op-code. Table 4±2 through Table 4±6 show the encoding of various addressing modes. Addressing mode bits (except immediate and flag addressing) come with an am, Rx and pm field. These are combined into a single field called {adrs}. The appropriate decoding and syntax for each ad- dressing mode with the {adrs} field is described in Table 4±4. The pm field only applies to indirect addressing. For other addressing modes, it is coded as zero.

Table 4±2. Addressing Mode Encoding

Bit

16 15 14 13 12 11

Opcode

next A

am contains addressing mode bits 5 ± 7. See Table 4±4 for details. Rx is the register being used. See for Table 4±3 for details.

pm is the post modification flag. See Table 4±3 for details.

next A is the accumulator pointer premodification field. See Table 4±5 for details.

Assembly Language Instructions

4-9

MSP50C614 specifications

The Texas Instruments MSP50C614 is a microcontroller that belongs to the MSP430 family, renowned for its low power consumption and versatile functionality. Primarily designed for embedded applications, this microcontroller is favored in various industries, including consumer electronics, industrial automation, and healthcare devices.

One of the standout features of the MSP50C614 is its ultra-low power technology, which enables it to operate in various power modes. This makes it ideal for battery-powered applications, where energy efficiency is crucial. The MSP430 architecture allows for a flexible power management system, ensuring that energy is conserved while providing robust performance.

The MSP50C614 is equipped with a 16-bit RISC CPU that delivers high performance while maintaining low power usage. With a maximum clock frequency of 16 MHz, it can execute most instructions in a single cycle, resulting in swift operation and responsive performance. This microcontroller also comes with a generous flash memory capacity, allowing developers to store large amounts of code and data conveniently.

In terms of peripherals, the MSP50C614 is highly versatile. It features a range of digital and analog input/output options, including multiple timers, GPIO ports, and various communication interfaces like UART, SPI, and I2C. This extensive set of peripherals allows for seamless integration with other components and simplifies the design of complex systems.

The integrated 12-bit Analog-to-Digital Converter (ADC) stands out as a valuable characteristic of the MSP50C614. This feature enables the microcontroller to convert physical analog signals into digital data, making it particularly useful for sensing applications and real-time monitoring.

Another noteworthy technology employed in the MSP50C614 is its support for low-voltage operations. With a broad supply voltage range, this microcontroller can function efficiently in diverse environments and is suitable for low-power applications, enhancing its practicality.

Moreover, Texas Instruments provides software support in the form of Code Composer Studio and various libraries that make it easier for developers to program and utilize the MSP50C614 effectively.

In summary, the Texas Instruments MSP50C614 microcontroller is a powerful, low-power solution equipped with the features and technologies necessary for efficient operation in a wide array of applications. Its blend of performance, flexibility, and energy efficiency makes it a popular choice among engineers and designers looking to create innovative, sustainable designs in the rapidly evolving tech landscape.

Texas Instruments MSP50C614 manual Addressing Modes, ±2. Addressing Mode Encoding, Opcode, Next a

Models: MSP50C614