SPI Receive Interrupt Operation

USART Operation: SPI Mode

The URXIFGx interrupt flag is set each time a character is received and loaded into UxRXBUF as shown in Figure 14−11 and Figure 14−12. 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 or when UxRXBUF is read.

Figure 14−11.Receive Interrupt Operation

SYNC

Valid Start Bit

Receiver Collects Character

		URXSE
From URXD		τ

BRK

URXEIE

URXWIE

RXWAKE

Clear

(S)

Clear

Character Received

URXS	SYNC = 1

URXIEx Interrupt Service

Requested

URXIFGx

SWRST

PUC

UxRXBUF Read

URXSE

IRQA

Figure 14−12. Receive Interrupt State Diagram

	SWRST = 1
Wait For Next		URXIFGx = 0
Start		URXIEx = 0
Receive		SWRST = 1
Receive
Character	USPIEx = 0	PUC	USPIEx = 0
		PUC
Receive	USPIEx = 1		USPIEx = 1 and	Interrupt
Receive				Service Started,
Character				Service Started,
Character		URXIFGx = 1		GIE = 0
Completed			URXIEx = 1 and	GIE = 0
Completed			URXIEx = 1 and	URXIFGx = 0
			GIE = 1 and	URXIFGx = 0
			GIE = 1 and
		Priority	Priority Valid
		Too	GIE = 0
		Too

Low

14-12USART Peripheral Interface, SPI 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 SPI Receive Interrupt Operation, 12. Receive Interrupt State Diagram

Models: MSP430x1xx