Common definitions for the use of TRBNets datafields

Packet types

The packet type is sent with each 64 bit packet

Name	Type	Description	F1	F2	F3
DAT	0x0	Normal data word	Data
HDR	0x1	Transfer start / source changed	Source adress	Target adress	SEQNR / DTYPE
EOB	0x2	End of Buffer		Data count	Checksum
TRM	0x3	Transfer Terminated	Error pattern		SEQNR / DTYPE
EXT	0x4	Extended data word	special data word for error detection
ACK	0x5	Buffer acknowledge	res.	Length of buffer	res.
SIG	0x6	Signals	future option
ILL	0x7	Illegal word - ignore	Data

-- Oct 2008: The packet size is going to be changed to 80 bit for better compatibility with 32 bit data words.

Name	Type	Description	H0	F0	F1	F2	F3
DAT	0x0	Normal data word		Data	Data	Data	Data
HDR	0x1	Transfer start / source changed		Source adress	Target adress		SEQNR / DTYPE
EOB	0x2	End of Buffer		Checksum		Data count	Buffer number
TRM	0x3	Transfer Terminated		Checksum	Error pattern	Error pattern	SEQNR / DTYPE
EXT	0x4	Extended data word		special data word for error detection
ACK	0x5	Buffer acknowledge			Length of buffer		Buffer number
SIG	0x6	Signals		future option
ILL	0x7	Illegal word - ignore		invalid	invalid	invalid	invalid

EXT and SIG are not implemented yet. EXT can for example be used for a CRC.

H0 is the packet start word: Bit 2-0: Packet type, Bit 3: init/reply channel, Bit 5-4: channel.

Data types

The datatype is a four bit value called dtype that is sent in each header and termination to specify the kind of data that is transfered. The definition for each datatype varies from channel to channel, the free usable values can also be selected for each endpoint seperatly.

Data Type	TRG1	IPU Data	Slow Control
0	trigger type	tbd	not used
1	"	tbd	not used
2	"	tbd	not used
3	"	tbd	not used
4	"	tbd	not used
5	"	tbd	not used
6	"	tbd	not used
7	"	tbd	not used
8	tbd	tbd	register read access
9	tbd	tbd	register write access
A	tbd	tbd	memory read access
B	tbd	tbd	memory write access
C	tbd	tbd	res.
D	tbd	tbd	res.
E	tbd	tbd	res.
F	tbd	tbd	network administration

The protocol for register and memory access on the slow control channel is defined in TrbNetRegIO. The network administration type is used for address assignment as described in TrbNetAddresses.

Broadcast Addresses

The network uses 9 different broadcast address for groups of network nodes. These are all addresses in the range above 0xFF00. The groups are selected by the BROADCAST_BITMASK generic in the top-level trbnet entity. Here, a negative logic is used, that means a '0' in the bitmask adds the board to the group given below.

Unset Bit	Bitmask	Broadcast Address	Type
-	FF	FFFF	all boards
0	FE	FFFE	Hubs
1	FD	FFFD	MDC OEPB
2	FB	FFFB	RICH ADCM
3	F7	FFF7	Shower AddOn
4	EF	FFEF	TRB using TDC
5	DF	FFDF	Ethernet-related
6	BF	FFBF
7	7F	FF7F

A Board can belong to more than one group by unsetting more than one bit in its configuration bitmask.

Error bits

The errorbits are 32 Bit data that are sent in each termination packet. For init transfers these are simply transported along with all other data. On the reply channel, the errorbits from all endpoints are merged using a or-logic.

Thus, for reply transfers these bits must be defined for all network members and should be 0 on normal operation.

The values for init transfers should not be hardcoded in any endpoint but constants defined in Trb_net_std should be used.

The lower 16 bit are flags common to all channels, while the upper 16 bit are channel dependend.

Common Error bits

Bit	Short Name	Description	Set by entity
0	endpoint reached	The addressed endpoint has be reached.	API
1	collision detected	A collision occured while sending the data. It is lost.	HUB
2	word missing	mismatch between packet counter and received number of packets	IBUF
3	checksum error	mismatch of given checksum with calculated one	IBUF
4	dont understand	addressed endpoint doesn't know how to treat received data	APL
5	buffer mismatch	received and internal buffer numbers do not match	IBUF
6	answer missing	One endpoint did not react	Hub
7
8
9
10
11
12
13
14
15

LVL1 trigger channel Errorbits

Bit	Short Name	Description	Set by entity
16	trigger counter mismatch	Trigger number received does not match internal counter value	ENDP
17	timing trigger missing	lvl1 trigger packet without timing trigger	ENDP
18
19
20	buffers half full	data buffers are filled to more than one half	APL
21	buffers almost full	data buffers are almost full	APL
22	not configured	FEE has not been configured correctly	APL
23
24
25
26
27
28
29
30
31

Data readout / IPU channel Errorbits

Bit	Short Name	Description	Set by entity
16	trigger number mismatch	Trigger number received does not match internal counter value	Hub
17	trigger code / random mismatch	Mismatch in second 16bit word of DHDR	Hub
18	wrong length	Length submitted in HDR does not match real length	Hub
19	answer missing	a board sent a short transfer instead of DHDR	Hub
20
21
22
23
24	not found	sent trigger number does not match stored events	APL
25	partially not found	parts of the data are missing	APL
26	severe problem	serious sync problem detected - intervention needed	APL
27	single broken event	event data corrupted, next event most likely not affected	APL
28
29
30
31

Slow control channel Errorbits

Bit	Short Name	Description	Set by entity
16	unknown address	No register / action is assigned to this address	RegIO
17	timeout	Application didn't react within given time limit	RegIO
18	nomoredata	Transfer was stopped with no more data signal	RegIO
19
20
21
22
23
24
25
26
27
28
29
30
31