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Request Event ID
Resend last message
Force pop Event ID
Force Request ID
0100
0101
0110
0111
Request an Event ID from the D-RORC.
Command the D-RORC to re-transmit the last message sent.
Command the D-RORC to pop one Event ID from its local queue.
Command the D-RORC to store the attached Request ID.
Table 5-17: Request commands.
5.8.1
•
Transmitter module VHDL Entity Hierarchy
Transmitter module
o Serial encoder
The Transmitter module is initiating the serial encoder and setting the masking vector.
5.8.2
Entity Transmitter module
The Transmitter module is initiating the serial encoder and setting the masking vector. A 16 bit register can be
accessed from the DCS bus as shown in figure 5-15. The register contains a message register and a channel
register.
temp_dcs_data
dcs_tx_channel
dcs_tx_data
15 – 8
7-0
Table 5-18: Bit map for DCS data.
The channel register selects which channel to be masked and unmasked the other channels. If the value in the
channels register does not specify a specific channel, all channels are unmasked and the message is
broadcasted to all channels. A flag is raised in to indicate that data are available to be written from the DCS
board to the message register. A state machine, see figure 5-16, in the controller sees the flag and starts
loading data into the serial encoder and sets the masking vector. The flag is removed and the procedure is
executed.
The Event ID module sends a request to the transmitter module and the request is granted if there is no pending
flag from the DCS bus. The controller loads data and the masking vector from the EventID module.
Messages are Hamming coded in the Transmitter module in an 8:4 code applied to the 4 bit command word and
request ID. The receiver (D-RORC) will discard data if it finds any errors. The Hamming function is in the
busylogic_pkg.