Bosch TTCAN - Manual (Page 26)

User’s Manual
BOSCH - 26/77 -
Revision 1.6 TTCAN
11.11.02
manual_about.fm
NewDat New Data
one
The Message Handler or the CPU has written new data into the data por-
tion of this Message Object.
zero No new data has been written into the data portion of this Message Object
by the Message Handler since last time this flag was cleared by the CPU.
MsgLst Message Lost (only valid for Message Objects with direction = receive)
one The Message Handler stored a new message into this object when New-
Dat was still set, the CPU has lost a message.
zero No message lost since last time this bit was reset by the CPU.
RxIE Receive Interrupt Enable
one
IntPnd will be set after a successful reception of a frame.
zero IntPnd will be left unchanged after a successful reception of a frame.
TxIE Transmit Interrupt Enable
one
IntPnd will be set after a successful transmission of a frame.
zero IntPnd will be left unchanged after the successful transmission of a frame.
IntPnd Interrupt Pending
one
This message object is the source of an interrupt. The Interrupt Identifier
in the Interrupt Register will point to this message object if there is no
other interrupt source with higher priority.
zero This message object is not the source of an interrupt.
RmtEn Remote Enable
one
At the reception of a Remote Frame, TxRqst is set.
zero At the reception of a Remote Frame, TxRqst is left unchanged.
TxRqst Transmit Request
one
The transmission of this Message Object is requested and is not yet done.
zero This Message Object is not waiting for transmission.
Note : In TTCAN mode, there are two types of transmit Message Objects. When NewDat is set and
TxRqst is reset, the message will be transmitted periodically at each Transmit_Trigger for this
message, without changing NewDat or TxRqst. When both NewDat and TxRqst are set, the
message will be transmitted once at a Transmit_Trigger for this message, inside an arbitrating
time window. When the transmission was not successful, it will be repeated at the next
Transmit_Trigger for this message. When the transmission was successful, NewDat is reset.
DLC3-0 Data Length Code
0-8
Data Frame has 0-8 data bytes.
9-15 Data Frame has 8 data bytes
Note : The Data Length Code of a Message Object must be defined the same as in all the correspond-
ing objects with the same identifier at other nodes. When the Message Handler stores a data
frame, it will write the DLC to the value given by the received message.