Flash Memory Operation

Initiating an Erase from Within Flash Memory

Any erase cycle can be initiated from within flash memory or from RAM. When a flash segment erase operation is initiated from within flash memory, all timing is controlled by the flash controller, and the CPU is held while the erase cycle completes. After the erase cycle completes, the CPU resumes code execution with the instruction following the dummy write.

When initiating an erase cycle from within flash memory, it is possible to erase the code needed for execution after the erase. If this occurs, CPU execution will be unpredictable after the erase cycle.

The flow to initiate an erase from flash is shown in Figure 5−5.

Figure 5−5. Erase Cycle from Within Flash Memory

Disable all interrupts and watchdog

Setup flash controller and erase

mode

Dummy write

Set LOCK=1, re-enable Interrupts

and watchdog

;Segment Erase from flash. 514 kHz < SMCLK < 952 kHz

;Assumes ACCVIE = NMIIE = OFIE = 0.

MOV

#WDTPW+WDTHOLD,&WDTCTL

; Disable WDT

DINT

 

; Disable interrupts

MOV

#FWKEY+FSSEL1+FN0,&FCTL2

; SMCLK/2

MOV

#FWKEY,&FCTL3

; Clear LOCK

MOV

#FWKEY+ERASE,&FCTL1

; Enable segment erase

CLR

&0FC10h

; Dummy write, erase S1

MOV

#FWKEY+LOCK,&FCTL3

; Done, set LOCK

...

 

; Re-enable WDT?

EINT

 

; Enable interrupts

5-6

Flash Memory Controller

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Texas Instruments MSP430x1xx manual Initiating an Erase from Within Flash Memory, 5. Erase Cycle from Within Flash Memory
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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.
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