Block Diagram
http://www.motorola.com/computer/literature
3-15
3
Figure 3-2. Serial Port Signal Multiplexing
Signal Multiplexing (MX)
There are four pins that are used for the MX function: MXCLK,
MXSYNC#, MXDO, and MXDI. MXCLK is the 10MHz bit clock for the
time-multiplexed data lines MXDO and MXDI. MXSYNC# is asserted for
one bit time at Time Slot 15 by the MCP750 board. MXSYNC# is used by
the transition module to synchronize with the MCP750 board. MXDO is
the time-multiplexed output line from the main board and MXDI is the
time-multiplexed line from the transition module. A 16-to-1 multiplexing
scheme is used with 10MHz bit rate. Sixteen Time Slots are defined and
allocated as follows:
Serial
J3
MX
Serial
MXDO
MXSYNC#
MXCLK
MXDI
Connector
3
4
Function