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Intel 8XC251SP, 8XC251SA, 8XC251SQ, 8XC251SB Chapter Programming and Verifying Nonvolatile Memory

Models: Embedded Microcontroller 8XC251SP 8XC251SA 8XC251SQ 8XC251SB

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CHAPTER 14

PROGRAMMING AND VERIFYING

NONVOLATILE MEMORY

This chapter provides instructions for programming and verifying on-chip nonvolatile memory on the 8XC251Sx. The programming instructions cover the entry of program code into on-chip code memory, configuration information into the on-chip configuration bytes, and other catego- ries of information into on-chip memory outside the memory address space. The verify instruc- tions permit reading these memory locations to verify their contents. The operations covered in this chapter are:

• programming and verifying the on-chip code memory

(8 Kbytes, 16 Kbytes)

• programming and verifying the on-chip configuration bytes

(8 bytes)

• programming and verifying the lock bits

(3 bits)

•

programming the encryption array

(128 bytes)

•

verifying the signature bytes

(3 bytes)

Programming instructions apply to the 87C251Sx (one-time programmable ROM (OTPROM) and erasable programmable ROM (EPROM)). Verify instructions apply to the 87C251Sx, the 83C251Sx (mask ROM), and the configuration bytes on the 80C251SB, SQ (no ROM/OTPROM/ EPROM). In the unprogrammed state, EPROM and OTPROM contains all 1s.

14.1 GENERAL

The 87C251Sx is programmed and verified in the same manner as the 87C51FX, using the same quick-pulse programming algorithm, which programs at VPP = 12.75 V using a series of five 100-µs PROG# pulses per byte. This results in a programming time of approximately 16 seconds for the 16-Kbyte on-chip code memory.

Programming and verifying operations differ from normal microcontroller operation. Memory accesses are made one byte at a time, input/output ports are used in a different manner, and the EA#/VPP and ALE/PROG# pins are used for their alternative (programming) functions. For a complete list of signal descriptions, see Appendix B.

14-1

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Intel 8XC251SP, 8XC251SA, 8XC251SQ, 8XC251SB, Embedded Microcontroller Chapter Programming and Verifying Nonvolatile Memory
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Embedded Microcontroller, 8XC251SP, 8XC251SA, 8XC251SQ, 8XC251SB specifications

The Intel 8XC251 series of embedded microcontrollers is a family of versatile and powerful devices, designed to meet the demands of a wide range of applications. With models such as the 8XC251SB, 8XC251SQ, 8XC251SA, and 8XC251SP, this series offers unique features while maintaining a high level of performance and reliability.

At the heart of the 8XC251 microcontrollers is the 8051 architecture, which provides a 16-bit processor capable of executing complex instructions efficiently. This architecture not only allows for a rich instruction set but also facilitates programming in assembly language and higher-level languages like C, which are essential for developing sophisticated embedded systems.

One of the significant features of the 8XC251 family is its integrated peripherals, including timer/counters, serial communication interfaces, and interrupt systems. These peripherals enable developers to implement timing functions, data communication, and real-time processing, all of which are crucial in modern embedded applications. The 8XC251SB and 8XC251SQ models, for instance, come equipped with multiple I/O ports that allow for interfacing with other devices and systems, enhancing their functionality in various environments.

The memory architecture of the 8XC251 devices is noteworthy, featuring on-chip ROM, RAM, and EEPROM. The on-chip memory allows for fast access times, which is essential for executing programs efficiently. Moreover, the EEPROM serves as non-volatile memory, enabling the storage of configuration settings and important data that must be retained even when power is lost.

In terms of operating voltage, the 8XC251 devices are designed to operate in a wide range, typically between 4.0V and 6.0V. This flexibility makes them suitable for battery-powered applications, where energy efficiency is critical. The power management features, including reduced power modes, further enhance their suitability for portable devices.

Lastly, the 8XC251 series is supported by a wide range of development tools and resources, allowing engineers and developers to streamline the development process. This support, combined with the microcontrollers' robust features, makes the Intel 8XC251 family a reliable choice for various embedded applications, such as industrial automation, automotive systems, and consumer electronics.

Overall, the Intel 8XC251SB, 8XC251SQ, 8XC251SA, and 8XC251SP deliver high performance, versatility, and ease of use, making them a preferred choice for embedded system designers looking to develop efficient and effective solutions.