87C196CB SUPPLEMENT

7.7DETERMINING THE CAN CONTROLLER’S INTERRUPT STATUS

A successful reception or transmission or a change in the status register can cause the CAN con- troller to generate an interrupt request. The INT_PEND1 register (see Table 7-2 on page 7-3) in- dicates whether a CAN interrupt request is pending. The CAN interrupt pending register (Figure 7-19) indicates the source of the request (either the status register or a specific message object). Your interrupt service routine should read the CAN_INT register to ensure that no additional in- terrupts are pending before executing the return instruction.

CAN_INT

Address:

1E5FH

read-only (87C196CB)

Reset State:

00H

The CAN interrupt pending (CAN_INT) register indicates the source of the highest priority pending interrupt. If a status change generated the interrupt request, software can read the status register (CAN_STAT) to determine whether the interrupt request was caused by an abnormal error rate, a successful reception, a successful transmission, or a new error. If an individual message object generated the interrupt request, software can read the associated message object control 0 register (CAN_MSGxCON0). The INT_PND bit-pair will be set, indicating that a receive or transmit interrupt request is pending.

87C196CB

7

0

Pending Interrupt

Bit

 

 

Function

Number

 

 

 

 

 

 

 

 

7:0

Pending Interrupt

 

 

This field indicates the source of the highest priority pending interrupt.

 

Value

Pending Interrupt

Priority (15 is highest; 0 is lowest)

 

00H

none

—

 

01H

status register

15

 

02H

message object 15

14

 

03H

message object 1

13

 

04H

message object 2

12

 

05H

message object 3

11

 

06H

message object 4

10

 

07H

message object 5

9

 

08H

message object 6

8

 

09H

message object 7

7

 

0AH

message object 8

6

 

0BH

message object 9

5

 

0CH

message object 10

4

 

0DH

message object 11

3

 

0EH

message object 12

2

 

0FH

message object 13

1

 

10H

message object 14

0

 

 

 

 

Figure 7-19. CAN Interrupt Pending (CAN_INT) Register

If a status change generated the interrupt (CAN_INT = 01H), software can read the CAN status register (Figure 7-20) to determine the source of the interrupt request.

7-32

Page 92 Page 94
Page 93
Image 93
Intel 8XC196NT user manual Determining the can CONTROLLER’S Interrupt Status, Canint, Read-only 87C196CB
Page 92 Page 94

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.
Top Page Image Contents