87C196CB SUPPLEMENT

7.5.2Programming the Message Object Identifier

Each message identifier register (Figure 7-13) specifies the message’s identifier. For messages with extended identifiers, write the identifier to bits ID28:0. For messages with standard identi- fiers, write the identifier to bits ID28:18. Software can change the identifier during normal oper- ation without requiring a subsequent device reset. Clear the MSGVAL bit in the corresponding message control register 0 to prevent the CAN controller from accessing the message object while the modification takes place, then set the bit to allow access.

CAN_MSGxID0–3 †

Address:

1Ex5H,

1Ex4H,

x = 1–15 (87C196CB)

 

1Ex3H,

1Ex2H

 

 

(x = 1–F)

 

Reset State:

Unchanged

Write the message object’s identifier to the CAN message object x identifier (CAN_MSGxID0–3) register. Software can change the identifier during normal operation. Clear the MSGVAL bit in the corresponding CAN_MSGxCON0 register to prevent the CPU from accessing the message object, change the identifier in CAN_MSGxID0–3, then set the MSGVAL bit to allow access.

87C196CB

31

 

 

 

CAN_MSGxID3

ID4

ID3

ID2

ID1

 

23

 

 

 

 

 

 

 

 

CAN_MSGxID2

ID12

ID11

ID10

ID9

 

15

 

 

 

 

 

 

 

 

CAN_MSGxID1

ID20

ID19

ID18

ID17

 

7

 

 

 

 

 

 

 

 

CAN_MSGxID0

ID28

ID27

ID26

ID25

 

 

 

 

 

 

 

 

24

ID0

—

—

—

 

 

 

16

 

 

 

 

ID8

ID7

ID6

ID5

 

 

 

8

 

 

 

 

ID16

ID15

ID14

ID13

 

 

 

0

 

 

 

 

ID24

ID23

ID22

ID21

 

 

 

 

Bit

Bit

Function

Number

Mnemonic

 

 

 

 

31:27

ID4:0

Message Identifier 17:0

23:16

ID12:5

These bits hold the 18 least-significant bits of an extended identifier. If

12:8

ID17:13

you write an extended identifier to these bits, but specify a standard

 

 

 

 

identifier (XTD = 0) in the corresponding message object’s configuration

 

 

register (CAN_MSGxCFG), the CPU clears these bits (ID17:0).

 

 

 

26:24

—

Reserved; for compatibility with future devices, write zeros to these bits.

 

 

 

15:13

ID20:18

Message Identifier 28:18

7:0

ID28:21

These bits hold either an entire standard identifier or the 11 most-

 

 

 

 

significant bits of an extended identifier.

 

 

 

†This register is the same as the arbitration register in the standalone 82527 CAN peripheral.

Figure 7-13. CAN Message Object x Identifier (CAN_MSGxID0–3) Register

7-22

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Intel 8XC196NT Programming the Message Object Identifier, Canmsg xID0-3 †, ID4 ID3 ID2 ID1, ID9, ID0 ID8 ID7 ID6 ID5
Page 82 Page 84

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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