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Intel 8XC251SB, 8XC251SA, 8XC251SP Configuration Bits, External Addresses for Configuration Array

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

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8XC251SA, SB, SP, SQ USER’S MANUAL

Table 4-1. External Addresses for Configuration Array

Size of External

Address of

Address of

Address Bus

Configuration Array on

Configuration Bytes

(Bits)

External Bus (2)

on External Bus (1)

 

 

 

16

FFF8H–FFFFH

UCONFIG1: FFF9H

 

 

UCONFIG0: FFF8H

 

 

 

17

1FFF8H–1FFFFH

UCONFIG1: 1FFF9H

 

 

UCONFIG0: 1FFF8H

 

 

 

18

3FFF8H–3FFFFH

UCONFIG1: 3FFF9H

 

 

UCONFIG0: 3FFF8H

 

 

 

NOTES:

 

 

1.When EA# = 0, the reset routine retrieves UCONFIG0 and UCONFIG1 from external memory using internal addresses FF:FFF8H and FF:FFF9H, which appear on the microcontroller external address bus (A17, A16, A15:0).

2.The upper six bytes of the configuration array are reserved for future use.

4.3THE CONFIGURATION BITS

This section provides a brief description of the configuration bits contained in the configuration bytes (Figures 4-3 and 4-4). UCONFIG0 and UCONFIG1 have five wait state bits: WSA1:0#, WSB1:0#, and WSB.

•UCON. Configuration byte location selector.

•SRC. Selects source mode or binary mode opcode configuration.

•INTR. Selects the bytes pushed onto the stack by interrupts.

•EMAP#. Maps on-chip code memory (16-Kbyte devices only) to memory region 00:.

The following bits configure the external memory interface.

•PAGE#. Selects page/nonpage mode and specifies the data port.

•RD1:0. Selects the number of external address bus pins and the address range for RD#, WR, and PSEN#. See Table 4-2.

•XALE#. Extends the ALE pulse.

•WSA1:0#. Selects 0, 1, 2, or 3 pre-programmed wait states for all regions except 01:.

•WSB1:0#. Selects 0 - 3 pre-programmed wait states for memory region 01:.

•EMAP#. Affects the external memory interface in that, when asserted, addresses in the range 00:E000H–00:FFFH access on-chip memory.

4-4

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Intel 8XC251SB, 8XC251SA, 8XC251SP Configuration Bits, External Addresses for Configuration Array, Size of External Address
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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.