TTCAN

User’s Manual

Revision 1.6

manual_about.fm

ClrIntPnd Clear Interrupt Pending Bit

Note : When writing to a Message Object, this bit is ignored.

TxRqst/NewDatAccess Transmission Request Bit one set TxRqst bit

zero TxRqst bit unchanged

Note : If a transmission is requested by setting TxRqst/NewDat in the IFx Command Mask Register, bit TxRqst in the IFx Message Control Register will be ignored.

Data A Access Data Bytes 0-3

one transfer Data Bytes 0-3 to Message Object. zero Data Bytes 0-3 unchanged.

Data B Access Data Bytes 4-7

one transfer Data Bytes 4-7 to Message Object. zero Data Bytes 4-7 unchanged.

3.3.1.2 Direction = Read

Mask Access Mask Bits

one transfer Identifier Mask + MDir + MXtd to IFx Message Buffer Register. zero Mask bits unchanged.

Arb

Access Arbitration Bits

 

one

transfer Identifier + Dir + Xtd + MsgVal to IFx Message Buffer Register.

 

zero

Arbitration bits unchanged.

Control

Access Control Bits

 

one

transfer Control Bits to IFx Message Buffer Register.

 

zero

Control Bits unchanged.

ClrIntPnd

Clear Interrupt Pending Bit

 

one

clear IntPnd bit in the Message Object.

 

zero

IntPnd bit remains unchanged.

TxRqst/NewDatAccess New Data Bit

one clear NewDat bit in the Message Object. zero NewDat bit remains unchanged.

Note : A read access to a Message Object can be combined with the reset of the control bits IntPnd and NewDat. The values of these bits transferred to the IFx Message Control Register always reflect the status before resetting them.

Data A Access Data Bytes 0-3

one transfer Data Bytes 0-3 to IFx Message Buffer Register. zero Data Bytes 0-3 unchanged.

Data B Access Data Bytes 4-7

one transfer Data Bytes 4-7 to IFx Message Buffer Register. zero Data Bytes 4-7 unchanged.

Note : The speed of the message transfer does not depend on how many bytes are transferred.

3.3.2 IFx Command Request Registers

A message transfer is started as soon as the CPU has written the message number to low byte of the Command Request Register. With this write operation, the Busy bit is automatically set to ‘1’ to notify the CPU that a transfer is in progress. After a wait time of 3 to

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Bosch Appliances TTCAN user manual Direction = Read, Control, ClrIntPnd, IFx Command Request Registers