SIGNAL DESCRIPTIONS

 

 

Table A-3. Signal Descriptions (Continued)

Name

Type

Description

 

 

 

EA#

I

External Access

 

 

This input determines whether memory accesses to special-purpose and

 

 

program memory partitions (FF2000–FF9FFFH) are directed to internal or

 

 

external memory. These accesses are directed to internal memory if EA# is

 

 

held high and to external memory if EA# is held low. For an access to any other

 

 

memory location, the value of EA# is irrelevant.

 

 

EA# also controls entry into programming mode. If EA# is at VPP voltage

 

 

(typically +12.5 V) on the rising edge of RESET#, the device enters

 

 

programming mode.

 

 

NOTE: Systems with EA# tied inactive have idle time between external bus

 

 

cycles. When the address/data bus is idle, you can use ports 3 and 4

 

 

for I/O. Systems with EA# tied active cannot use ports 3 and 4 as

 

 

standard I/O; when EA# is active, these ports will function only as the

 

 

address/data bus.

 

 

EA# is sampled and latched only on the rising edge of RESET#. Changing the

 

 

level of EA# after reset has no effect.

 

 

On devices with no internal nonvolatile memory, always connect EA# to VSS.

EPA9:0

I/O

Event Processor Array (EPA) Input/Output pins

 

 

These are the high-speed input/output pins for the EPA capture/compare

 

 

channels. For high-speed PWM applications, the outputs of two EPA channels

 

 

(either EPA0 and EPA1 or EPA2 and EPA3) can be remapped to produce a

 

 

PWM waveform on a shared output pin.

 

 

EPA9:0 are multiplexed as follows: EPA0/P1.0/T2CLK, EPA1/P1.1,

 

 

EPA2/P1.2/T2DIR, EPA3/P1.3, EPA4/P1.4, EPA5/P1.5, EPA6/P1.6, EPA7/P1.7,

 

 

EPA8/P6.0/COMP0, and EPA9/P6.1/COMP1.

EPORT.7:0

I/O

Extended Addressing Port

(100-pin CB)

 

This is a 4-bit, bidirectional, memory-mapped I/O port.

 

 

 

 

EPORT.7:0 are multiplexed with A23:16.

EPORT.3:0

I/O

Extended Addressing Port

(84-pin CB)

 

This is a 4-bit, bidirectional, memory-mapped I/O port.

 

 

 

 

EPORT.3:0 are multiplexed with A19:16.

EXTINT

I

External Interrupt

 

 

In normal operating mode, a rising edge on EXTINT sets the EXTINT interrupt

 

 

pending bit. EXTINT is sampled during phase 2 (CLKOUT high). The minimum

 

 

high time is one state time.

 

 

In powerdown mode, asserting the EXTINT signal for at least 50 ns causes the

 

 

device to resume normal operation. The interrupt need not be enabled, but the

 

 

pin must be configured as a special-function input. If the EXTINT interrupt is

 

 

enabled, the CPU executes the interrupt service routine. Otherwise, the CPU

 

 

executes the instruction that immediately follows the command that invoked the

 

 

power-saving mode.

 

 

In idle mode, asserting any enabled interrupt causes the device to resume

 

 

normal operation.

 

 

EXTINT is multiplexed with P2.2 and PROG#.

A-7

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Intel 87C196CB, 8XC196NT user manual Ea#, EPORT.70, EPORT.30
Page 127 Page 129

8XC196NT, 87C196CB specifications

The Intel 87C196CB and 8XC196NT are microcontrollers from the C196 family, which was designed to meet the demands of embedded control technology. These microcontrollers are popular in various applications due to their robust architecture, extensive I/O capabilities, and specialized functionality, making them ideal for automotive, industrial, and communication systems.

The 87C196CB is distinguished by its 16-bit architecture, offering a balance of processing power and efficiency. It features a 16-bit data bus, which allows for fast data processing, and a 16-bit address bus, supporting up to 64KB of program memory. The microcontroller integrates on-chip memory, including 2KB of ROM and 128 bytes of RAM, which facilitates faster execution of programs and data handling.

One of the standout features of the 87C196CB is its versatility in I/O operations. It comes equipped with 32 general-purpose I/O lines that can be configured for various functions, including input, output, and interrupt handling. This flexibility enables developers to optimize the microcontroller for their specific application needs.

The 8XC196NT builds on the capabilities of its predecessor, offering advanced functionalities such as an enhanced instruction set and integrated peripherals. It includes additional features like timers, serial communication interfaces, and analog-to-digital converters, which expand its usability in complex embedded systems. The 8XC196NT supports multiple addressing modes, allowing for more efficient programming and memory management.

Both microcontrollers utilize innovative technologies that improve performance and power efficiency. The on-chip operating system support aids in real-time processing and multitasking, making them suitable for time-sensitive applications. Power management features are also incorporated, allowing these microcontrollers to operate in low-power modes, which is crucial for battery-operated devices.

The 87C196CB and 8XC196NT microcontrollers are characterized by their reliability and long service life, meeting the stringent demands of industrial applications. Their ability to perform tasks rapidly, combined with their diverse peripheral support, makes them popular choices among engineers and developers designing embedded systems. Overall, the Intel 87C196CB and 8XC196NT microcontrollers remain relevant in the rapidly evolving landscape of embedded technology, facilitating innovative solutions across various industries.
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