Usart Receive Interrupt Operation

USART Operation: UART Mode

The URXIFGx interrupt flag is set each time a character is received and loaded into UxRXBUF. An interrupt request is generated if URXIEx and GIE are also set. URXIFGx and URXIEx are reset by a system reset PUC signal or when SWRST = 1. URXIFGx is automatically reset if the pending interrupt is served (when URXSE = 0) or when UxRXBUF is read. The operation is shown in Figure 13−11.

Figure 13−11.Receive Interrupt Operation

	SYNC
	Valid Start Bit	S
Receiver Collects Character		S
Receiver Collects Character
	URXSE
From URXD	τ	Clear
		Clear
Erroneous Character Rejection
PE
FE
BRK	URXEIE
	URXEIE	S
		S
URXWIE		Clear
RXWAKE
Non-Address Character Rejection		Character Received
Non-Address Character Rejection		or
		or
		Break Detected

URXS

	URXIEx				Interrupt Service
	URXIEx				Requested

URXIFGx

SWRST

PUC

UxRXBUF Read

URXSE

IRQA

URXEIE is used to enable or disable erroneous characters from setting URXIFGx. When using multiprocessor addressing modes, URXWIE is used to auto-detect valid address characters and reject unwanted data characters.

Two types of characters do not set URXIFGx:

-Erroneous characters when URXEIE = 0

-Non-address characters when URXWIE = 1

When URXEIE = 1 a break condition will set the BRK bit and the URXIFGx flag.

13-18USART Peripheral Interface, UART Mode

MSP430x1xx specifications

The Texas Instruments MSP430x1xx series is a family of ultra-low-power microcontrollers that are highly regarded in the embedded systems community for their versatility and performance. Designed for applications ranging from portable instrumentation to low-power industrial devices, the MSP430x1xx combines flexibility and efficiency with advanced features tailored for energy-sensitive applications.

One of the standout characteristics of the MSP430x1xx is its ultra-low-power operation. This series offers several low-power modes that can significantly extend battery life in portable devices. The microcontroller can be in active mode, low-power mode, or even in a deep sleep state, allowing developers to optimize power consumption based on the application's requirements. In fact, some configurations can operate at just a few microamps, making it ideal for battery-operated devices.

Another key feature is the 16-bit RISC architecture that provides powerful processing capabilities while maintaining a low power profile. The MSP430x1xx series supports a maximum clock speed of 16 MHz, allowing for efficient task execution while consuming minimal energy. This architecture ensures that programs run smoothly while the microcontroller remains energy efficient.

The MSP430x1xx is equipped with various integrated peripherals, including analog-to-digital converters (ADCs), timers, and communication interfaces like UART, SPI, and I2C. The inclusion of a powerful ADC enables the microcontroller to handle sensor readings with high accuracy, making it suitable for applications like environmental monitoring and medical devices. The integrated timers provide essential functionality for real-time applications, allowing for event-driven programming and precise timing control.

Memory options in the MSP430x1xx series are also robust, with configurations offering flash memory sizes from 1 KB to 64 KB. This flexibility allows developers to choose the optimal memory size for their specific applications, accommodating a wide range of requirements.

Additionally, the MSP430x1xx microcontrollers are designed with a wide operating voltage range, typically from 1.8V to 3.6V, making them compatible with various power sources and further enhancing their usability in diverse applications.

In summary, the Texas Instruments MSP430x1xx series of microcontrollers is an excellent choice for developers seeking low-power, high-performance solutions for embedded applications. With an efficient architecture, a rich set of peripherals, and flexible memory options, these microcontrollers are positioned to meet the growing demands of modern electronic designs, particularly in battery-powered and energy-sensitive applications.

Texas Instruments MSP430x1xx Usart Receive Interrupt Operation, 11.Receive Interrupt Operation

Models: MSP430x1xx

USART Receive Interrupt Operation

Figure 13−11.Receive Interrupt Operation

MSP430x1xx specifications