Multi-Module Data Transfers (Multi-Block) - LeCroy 1881M Manual

1881M
Theory of Operation
In Memory Test Mode, the user has complete control over the data space NTA as well as the block transfer
word count (CSR5) and Read Page pointer (CSR16). Re-reads can be accomplished as with non-MTM.
Additionally, the user can re-read any buffer by setting RP to the buffer to be read, fetching the word count
for that event from the first location in that buffer (using a random read from Data Space), and loading
CSR5 directly with the block transfer word count.

5.4.3 Multi-Module Data Transfers (Multi-Block)

The 1881M fully supports the Multi-Module Data Transfer (MDT-1) specification. Assuming a group on
1881M modules has been configured for a MDT scan as per the specification, it must first be established
that all modules involved in the scan have data available. This could be done, for example, through a
broadcast LNE. The scan is initiated by addressing the primary link and beginning a FASTBUS block
read. The scan proceeds with each module participating, in turn, in the block read until the end link
completes its transfer and issues SS = 2.
It is important to realize that if all data words in an event are suppressed (a null event), a header word is
still written into the buffer for that event. Thus a module participating in a Multi-Block scan which has a
null event loaded for readout will still transfer the header word during its portion of the transfer.
5-7 July 23, 1998