HI-3200, HI-3201
Type 2 and 3 CAN Transmit Descriptor Opcode and Index Bytes
Type 2 and 3 CAN Transmit Discriptor Op-Code and Index byte pairs specify the source of data for their corresponding
CAN frame ID bits and data bytes. Their format and operation is similar to the ARINC 429 descriptor byte pairs:
Op-Code
Index
Value
CAN TRANSMIT OPCODE - INDEX BYTE PAIR
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
LSB
LSB
MSB
MSB
ACTION BYTE
VALUE BYTE
Op-Code
0X0
Index
Value
Description
XXXXX
LLLLLLLL
Immediate data. The value contained in the descriptor value data byte is
loaded into this byte position of the CAN Frame to be transmitted.
0X1
CCCXX
LLLLLLLL
Immediate data conditional. The NEWCAN bit corresponding to the ARINC
Data RAM location defined by channel “CCC” and label block “LLLLLLLL” is
read. LLLLLLLL is used if NEWCAN is set for this or any other
conditional opcode within this descriptor frame. If NEWCAN = 0 for all
conditional op codes (within this descriptor frame) then no transmission
occurs for this frame and the sequencer increments to the next descriptor
frame. The NEWCAN bit for the referencedARINC RAM block is reset.
100
101
CCCBB
CCCBB
LLLLLLLL
LLLLLLLL
Indexed data. The value of ARINC Data RAM location defined by channel
“CCC”, label block “LLLLLLLL” and byte number “BB” is loaded into this byte
position of the CAN frame to be transmitted.
Indexed data conditional. The NEWCAN bit corresponding to the ARINC
Data RAM location defined by channel “CCC”, label block “LLLLLLLL” and
byte number “BB” is read. The corresponding byte is used if
NEWCAN is set for this or any other conditional opcode within this
descriptor frame. If NEWCAN = 0 for all conditional op codes (within this
descriptor frame) then no transmission occurs for this frame and the
sequencer increments to the next descriptor frame. The NEWCAN bit for the
referencedARINC RAM block is reset.
110
111
XBBBB
XBBBB
NNNNNNNN
NNNNNNNN
CAN byte. The value of the byte at CAN RAM address filter block
“NNNNNNNN”, byte number “BBBB” is loaded into the CAN transmit buffer
byte position to be transmitted.
CAN byte conditional. The NEWCAN bit corresponding to the CAN RAM
address filter block “NNNNNNNN”, byte number “BBBB”
is read. The corresponding byte is used if NEWCAN is set for this or any
other conditional opcode within this descriptor frame. If NEWCAN = 0 for
all conditional op codes (within this descriptor frame) then ARINC word
construction is terminated, no transmission occurs for this frame and the
sequencer increments to the next descriptor frame. The NEWCAN bit for
the referenced CAN RAM address filter block is reset.
HOLT INTEGRATED CIRCUITS
36
HOLTIC [ HOLT INTEGRATED CIRCUITS ]
