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Intel 8XC196NP, 80C196NU, Microcontroller manual Eport Operation, Eport Control and Status Registers

Models: Microcontroller 80C196NU 8XC196NP

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8XC196NP, 80C196NU USER’S MANUAL

Table 7-10. EPORT Control and Status Registers

Mnemonic

Address

Description

 

 

 

EP_DIR

1FE3H

EPORT Direction

 

 

In I/O mode, each bit of EP_DIR controls the direction of the corre-

 

 

sponding pin. Clearing a bit configures a pin as a complementary

 

 

output; setting a bit configures a pin as either an input or an open-

 

 

drain output. (Open-drain outputs require external pull-ups).

 

 

Any pin that is configured for its extended-address function is forced

 

 

to the complementary output mode except during reset, hold, idle,

 

 

powerdown, and standby. (Standby mode is available only on the

 

 

80C196NU.)

 

 

 

EP_MODE

1FE1H

EPORT Mode

 

 

Each bit of EP_MODE controls whether the corresponding pin

 

 

functions as a standard I/O port pin or as an extended-address

 

 

signal. Setting a bit configures a pin as an extended-address signal;

 

 

clearing a bit configures a pin as a standard I/O port pin.

 

 

 

EP_PIN

1FE7H

EPORT Pin State

 

 

Each bit of EP_PIN reflects the current state of the corresponding

 

 

pin, regardless of the pin configuration.

 

 

 

EP_REG

1FE5H

EPORT Data Output

 

 

Each bit of EP_REG contains data to be driven out by the corre-

 

 

sponding pin. When a pin is configured as standard I/O

 

 

(EP_MODE.x = 0), the result of a CPU write to EP_REG is

 

 

immediately visible on the pin.

 

 

During nonextended data accesses, EP_REG contains the value of

 

 

the memory page that is to be accessed. For compatibility with

 

 

software tools, clear the EP_REG bit for any EPORT pin that is

 

 

configured as an extended-address signal (EP_MODE.x set).

 

 

80C196NU Only: For nonextended data accesses, the 80C196NU

 

 

forces the page address to 00H. You cannot change pages by

 

 

modifying EP_REG.

 

 

 

7.3.1EPORT Operation

As Figure 7-2 shows, each EPORT pin serves either as I/O or as an address line, as selected by the I/O multiplexer. This multiplexer is controlled by the EP_MODE register. If EP_MODE.x is clear (I/O mode), the pin serves as I/O until EP_MODE.x is changed.

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Intel 8XC196NP, 80C196NU, Microcontroller manual Eport Operation, Eport Control and Status Registers
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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.