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Intel 8XC196NP, 80C196NU manual Eport Considerations, Eport Status During Instruction Execution

Models: Microcontroller 80C196NU 8XC196NP

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8XC196NP, 80C196NU USER’S MANUAL

7.3.3EPORT Considerations

This section outlines considerations for using the EPORT pins.

7.3.3.1EPORT Status During Reset, CCB Fetch, Idle, Powerdown, and Hold

During reset, the EPORT pins are forced to their extended-address functions and are weakly pulled high. During the CCB fetch, FFH is strongly driven onto the pins. This value remains strongly driven until either the pin is configured for I/O or a different extended address is access- ed. If the pins remain configured as extended-address functions, they are placed in a high-imped- ance state during idle, powerdown, standby (80C196NU only), and hold. If they are configured as I/O, they retain their I/O function during those modes. See Figure 11-7 on page 11-8 and Table B-5 on page B-13 for additional information.

7.3.3.2EP_REG Settings for Pins Configured as Extended-address Signals

Nonextended data accesses go to the address contained in EP_REG. Therefore, if you configure EP_REG to point to the desired address, you can use nonextended addressing modes to access the extended address space. However, we recommend that you clear the EP_REG bits for any EPORT pins configured as extended-address signals in order to maintain compatibility with soft- ware development tools.

NOTE

If any pins are configured as extended-address signals and their corresponding EP_REG bits are set, nonextended operations will still access the register file and standard SFRs. However, all other nonextended accesses, including those to internal RAM and internal nonvolatile memory, will be directed off-chip to the “page” address in EP_REG.

The 8XC196NP allows you to change the value of EP_REG to control which memory page a nonextended instruction accesses. However, software tools require that EP_REG be equal to 00H. The 80C196NU forces all nonextended data accesses to page 00H. You cannot use EP_REG to change pages.

7.3.3.3EPORT Status During Instruction Execution

When using the EPORT to address memory outside page 00H, keep these points in mind:

1.During extended accesses, the upper four bits of the address (lower four bits of the EPC) are sent to the EPORT. EPORT pins configured for the extended-address function (EP_MODE.x set) output this address.

2.During nonextended accesses, EPORT pins configured for the extended-address function (EP_MODE.x set) output the value contained in EP_REG.

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Intel 8XC196NP, 80C196NU, Microcontroller manual Eport Considerations, Eport Status During Instruction Execution
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Microcontroller, 80C196NU, 8XC196NP specifications

The Intel 8XC196NP and 80C196NU microcontrollers are part of Intel's renowned 16-bit microcontroller series that gained popularity in the 1980s and 1990s for embedded systems applications. Designed for a variety of applications, these microcontrollers are characterized by their robust performance, versatility, and industry-standard architecture.

The 8XC196NP features an enhanced instruction set with over 100 instructions, allowing for efficient code execution. It operates at clock speeds up to 16 MHz, which contributes to improved performance in time-sensitive applications. The microcontroller is equipped with a 16-bit data bus, enabling more efficient data handling compared to its 8-bit predecessors, thus accommodating complex algorithms and large data sets.

In terms of memory architecture, the 8XC196NP supports an addressable memory space of up to 64 KB of program memory and 64 KB of data memory. This configuration provides sufficient space for large applications while ensuring fast data access. The microcontroller includes integrated features such as timers, serial I/O capabilities, and interrupt processing, which enhance its functionality for real-time applications and control mechanisms.

The 80C196NU, on the other hand, is designed for lower power operation, making it suitable for battery-powered devices. This microcontroller maintains similar features to the 8XC196NP while offering advancements that support low-power consumption. The 80C196NU can also function in a range of temperature environments, making it adaptable for industrial applications.

Both the 8XC196NP and 80C196NU support external memory interfacing, allowing designers to expand the system's capability by connecting additional ROM and RAM. This flexibility makes them appealing for developing complex systems, such as motor controls, industrial automation, and consumer electronics.

Another standout feature of these microcontrollers is their built-in debugging capabilities. Intel provided hardware and software tools that enabled developers to test and troubleshoot their applications effectively, reducing the development time and increasing reliability.

Overall, the Intel 8XC196NP and 80C196NU microcontrollers stand out for their dependability, versatility, and performance, contributing significantly to the evolution of embedded system design. Their legacy continues to influence modern microcontroller technology, ensuring their relevance in a wide array of applications today.