Philips Semiconductors

User’s Manual - Preliminary -

 

 

 

 

 

 

FLASH PROGRAM MEMORY

P89LPC901/902/903

 

ing to FMDATA. However, each location in the page register can only be written once following each LOAD command. Attempts to write to a page register location more than once should be avoided.

FMADRH and FMADRL[7:4] are used to select a page of code memory for the erase-program function. When the erase-pro- gram command is written to FMCON, the locations within the code memory page that correspond to updated locations in the page register will have their contents erased and programmed with the contents of their corresponding locations in the page register. Only the bytes that were loaded into the page register will be erased and programmed in the user code array. Other bytes within the user code memory will not be affected.

Writing the erase-program command (68H) to FMCON will start the erase-program process and place the CPU in a program- idle state. The CPU will remain in this idle state until the erase-program cycle is either completed or terminated by an interrupt. When the program-idle state is exited, FMCON will contain status information for the cycle.

If an interrupt occurs during an erase/programming cycle, the erase/programming cycle will be aborted and the OI flag (Opera- tion Interrupted) in FMCON will be set. If the application permits interrupts during erasing-programming, the user code should check the OI flag (FMCON.0) after each erase-programming operation to see if the operation was aborted. If the operation was aborted, the user’s code will need to repeat the process starting with loading the page register.

The erase-program cycle takes 4ms to complete, regardless of the number of bytes that were loaded into the page register.

Erasing-programming of a single byte (or multiple bytes) in code memory is accomplished using the following steps:

•Write the LOAD command (00H) to FMCON. The LOAD command will clear all locations in the page register and their corresponding update flags.

•Write the address within the page register to FMADRL. Since the loading the page register uses FMADRL[5:0], and since the erase-program command uses FMADRH and FMADRL[7:4], the user can write the byte location within the page register (FMADRL[3:0]) and the code memory page address (FMADRH and FMADRL[7:4]) at this time.

•Write the data to be programmed to FMDATA. This will increment FMADRL pointing to the next byte in the page register.

•Write the address of the next byte to be programmed to FMADRL, if desired. (Not needed for contiguous bytes since FMADRL is auto-incremented). All bytes to be programmed must be within the same page.

•Write the data for the next byte to be programmed to FMDATA.

•Repeat writing of FMADRL and/or FMDATA until all desired bytes have been loaded into the page register.

•Write the page address in user code memory to FMADRH and FMADRL[7:4], if not previously included when writing the page register address to FMADRL[3:0].

•Write the erase-program command (68H) to FMCON,starting the erase-program cycle.

•Read FMCON to check status. If aborted, repeat starting with the LOAD command.

An assembly language routine to load the page register and perform an erase/program operation is shown in Figure 14-2. A similar C-language routine is shown in Figure 14-3.

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Philips P89LPC903, P89LPC901, P89LPC902 user manual Flash Program Memory
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P89LPC903, P89LPC902, P89LPC901 specifications

The Philips P89LPC901, P89LPC902, and P89LPC903 are a series of 8-bit microcontrollers designed for embedded system applications. These models, which belong to the LPC900 series, are notable for their affordability and versatility, making them an attractive choice for both hobbyists and professional developers.

One of the core features of the P89LPC901, P89LPC902, and P89LPC903 microcontrollers is their powerful 8-bit architecture. Operating at clock speeds up to 20 MHz, they deliver efficient performance suited for a range of tasks. Each model includes a comprehensive instruction set that supports various data manipulation and arithmetic functions, enabling extensive programming capabilities.

These microcontrollers come with built-in memory, with configurations that vary among the three models. The P89LPC901 typically features 4 KB of Flash memory and 256 bytes of RAM, while the P89LPC902 and P89LPC903 offer enhanced memory options. This Flash memory allows for reprogrammability, making it easier to update and modify applications as needed.

Another significant characteristic of the LPC900 series is their integrated peripherals. These models are equipped with a variety of I/O ports, allowing for easy interfacing with other devices and components. The P89LPC901 supports up to 32 I/O pins, while the P89LPC902 and P89LPC903 provide additional features such as analog-to-digital converters (ADCs), timers, and serial communication interfaces. This broad range of peripherals empowers developers to design complex applications without needing extra hardware.

Power consumption is also a key consideration for microcontroller applications. The P89LPC901, P89LPC902, and P89LPC903 are designed with low power consumption in mind, making them ideal for battery-operated devices and energy-efficient projects. They can operate in various power modes, allowing for greater flexibility in deployment.

In terms of technology, these microcontrollers utilize advanced CMOS technology, ensuring high reliability and durability. Their design offers a robust solution for numerous applications, including consumer electronics, industrial controls, and automation systems.

In summary, the Philips P89LPC901, P89LPC902, and P89LPC903 microcontrollers present an attractive combination of performance, integrated peripherals, low power consumption, and versatility. Their features cater to a wide array of applications, keeping them relevant in a rapidly evolving technology landscape. For hobbyists and professionals alike, these microcontrollers represent a reliable foundation for embedded system development.
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