DEVICE CONFIGURATION

UCONFIG1 (1), (3)

7

—

—

—

INTR

 

 

 

 

Address:FF:FFF9H (2)

0

WSB WSB1# WSB0# EMAP#

 

Bit

Bit

 

 

Function

 

Number

Mnemonic

 

 

 

 

 

 

 

 

 

 

 

7:5

—

Reserved for internal or future use. Set these bits when programming

 

 

 

UCONFIG1.

 

 

 

 

 

 

 

4

INTR

Interrupt Mode:

 

 

 

 

If this bit is set, interrupts push 4 bytes onto the stack (the 3 bytes of the PC

 

 

 

and PSW1). If this bit is clear, interrupts push the 2 lower bytes of the PC

 

 

 

onto the stack. See 4.8, “Interrupt Mode (INTR).”

 

 

 

 

 

3

WSB

Wait State B. Use only for A-step compatibility:

 

 

 

Clear this bit to generate one external wait state for memory region 01:. Set

 

 

 

this bit for no wait states for region 01:.

 

 

 

 

 

2:1

WSB1:0#

External Wait State B (Region 01:):

 

 

 

WSB1#

WSB0#

 

 

 

 

0

0

Inserts 3 wait states for region 01:

 

 

 

0

1

Inserts 2 wait states for region 01:

 

 

 

1

0

Inserts 1 wait state for region 01:

 

 

 

1

1

Zero wait states for region 01:

 

 

 

 

 

 

0

EMAP#

EPROM Map:

 

 

 

 

For devices with 16 Kbytes of on-chip code memory, clear this bit to map the

 

 

 

upper half of on-chip code memory to region 00: (data memory). Maps

 

 

 

FF:2000H–FF:3FFFH to 00:E000H–00:FFFFH. If this bit is set, mapping

 

 

 

does not occur and addresses in the range 00:E000H–00:FFFFH access

 

 

 

external RAM. See 4.7, “Mapping On-chip Code Memory to Data Memory

 

 

 

(EMAP#).”

 

 

 

 

 

 

 

NOTES:

 

 

 

 

1.User configuration bytes UCONFIG0 and UCONFIG1 define the configuration of the 8XC251Sx.

2.Address. UCONFIG1 is the second-lowest byte of the 8-byte configuration array. As determined by UCON and EA#, the 8XC251SA, SB, SP, SQ fetches configuration information from on-chip nonvolatile memory at addresses FF:FFF8H and FF:FFF9H or from external memory using these same addresses. In external memory, configuration information is obtained from an 8-byte configuration array located at the highest addresses implemented. The physical location of the configuration array in external memory depends on the size and decode arrangement of the external memory (Table 4-1 and Figure 4-2).

3.Instructions for programming and verifying on-chip configuration bytes are given in Chapter 14.

Figure 4-4. Configuration Byte UCONFIG1

4-7

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Intel 8XC251SP, 8XC251SA, 8XC251SQ, 8XC251SB, Embedded Microcontroller manual UCONFIG1 1, WSB1# WSB0#
Page 70 Page 72

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.
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