Message Translation And Formatting - STMicroelectronics SPC572L series Reference Manual

Nexus Aurora Router (NAR)
or ORed together (ACC = 1). For example, to send ICT messages out the HBDP and all
other traffic to the trace memory bus port:
•
Set ALT = 10 in the NAR_CR—sets trace memory bus port as the alternate port
•
Set MSP = 01 in the NAR_CR—sets HBDP as the message select port
•
Set FE0 = 1 & TF0 = 100010 (0x22) in the NAR_TFR—enables type filter 0 to match
ICT messages
To send everything but data trace from source 13 to the trace memory bus port, while all
other traffic goes to the HBDP:
• Set ALT = 01 in the NAR_CR—sets HBDP as the alternate port
•
Set MSP = 10 in the NAR_CR—sets trace memory bus port as the message select port
• Set TFI = 1—inverts type-filter logic
•
Set FE0 = 1 & TF0 = 000101 (0x05) in the NAR_TFR to select data trace of size 8 bits
• Set FE1 = 1 & TF1 = 000110 (0x06) in the NAR_TFR to select data trace of size 16 bits
•
Set FE2 = 1 & TF2 = 001101 (0x0d) in the NAR_TFR to select data trace of size 32 bits
•
Set FE3 = 1 & TF3 = 001110 (0x0e) in the NAR_TFR to select data trace size of 64 bits
•
Set FE0 = 1 & SF0 = 001101 (0x0d) in the NAR_SFR to select source trace ID = 13
•
Set ACC = 0 in NAR_SFR so the final filter is ~(data_trace) AND (source = 13)HBDP
Data is written into the output queue at a maximum rate of one entry per cycle. If the current
messages source and type pass the filters, then the message is marked for the MSP. When
the entry is later pulled from the queue, it is then sent to the MSP. Unmarked entries are
sent to the alternate port. Message destination must be recalculated on every end-of-
message boundary, using the fixed-width SRC and TYPE fields at the beginning of each
Nexus message.
65.5.7

Message translation and formatting

The NAR performs the formatting on Nexus messages before sending them to an output
port. The exact translation performed depends on the destination port.
65.5.7.1 Aurora format
Nexus messages are pre-translated before sending to the HBDP using the Aurora protocol.
The NAR output is a stream of 16 × 4-bit words (where 4 is the width of the NAR Aurora out
port) that are further encoded by an external Aurora block before being sent for transmission
on the Aurora (HBDP) port.
Entries from the output queue are chopped into chunks of 4 × 16-bit words. The amount of
data that can be transmitted per Aurora cycle depends on the number of lanes available in
the HBDP (transmitted HBDP word = 16 × number of lanes).
65.5.7.2 Trace memory bus format
The trace memory bus works on AHB-EW protocol. Data destined for the trace memory bus
port is split back out into 32-bit beats (Nexus word). Depending on the relative sizes of the
beat and the width of the trace memory bus port, one or more Nexus words are packed into
a trace memory bus data word, with any remaining bits padded to 0.
For example, if the size of the beat = 32 and the width of the trace memory bus = 64, then
each trace memory bus data packet contains two beats of Nexus data. Since the data is
stored in a regular format (MSEO bits in same place at every location), this makes data
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