User`s guide

The XMI
The custom components in the XMI Corner are called XLATCH and
XCLOCK. Both components are implemented in CMOS and interface
node-specific logic to the XMI Corner components over the XMI Corner
interface (XCI) bus. The XMI Corner, in turn, interfaces directly to the
XMI bus. (See Figure 2–2.)
Each node has a set of three clock signals, which are distributed radially
to each node from a central source on the backplane. These clocks
are received by the XCLOCK chip, which then provides a set of clock
waveforms (XCI clocks) to the node-specific logic and the required control
lines (XL lines) for the seven XLATCH chips. The XLATCH chips provide
the interface to all the XMI lines except those directly interfaced to the
XCLOCK chip.
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