Install the Daisy-Chain Jumpers
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4-5
4
Install the Daisy-Chain Jumpers
All daisy-chain lines of the VME64x bus can be separately bypassed with
removable shorting jumpers on every connector socket. Shorting the input
to the output of the daisy-chain signals is required if the daisy-chains are
in use, and if a VME64x module design does not provide for the
propagation of the daisy-chain.
For instance, if a backplane slot contains a device module designed for
daisy-chain signal propagation, no jumpers are required on the jumper pins
for that slot. However, all empty slots, and slots containing modules
without this capability, must have daisy-chain jumpers installed to provide
propagation of these signals.
Daisy-chain bypass jumper areas are provided on the rear side of the
backplane. For an illustration of the backplane daisy-chain jumper wiring,
see Figure 4-2 on page 4-8.
The following procedure is suggested for installing the jumpers:
1. Attach an ESD strap to your wrist. Attach the other end of the ESD
strap to the chassis as a ground. The ESD strap must be secured to
your wrist and to ground throughout the procedure.
2. Perform an operating system shutdown. Turn the AC or DC power
off and remove the AC cord or DC power lines from the system.
3. At the rear of the backplane, select the row(s) of header pins that
require jumpers. Any backplane slot that will not be occupied by a
VME64x module requires jumpers on the rear backplane pins to
propagate the Bus Grant (BG) and Interrupt Acknowledge (IACK)
signals to the next VME64x module slot. See Figure 4-1 on page 4-4
and Table 4-2 on page 4-7.
For example: If a VME64x module is used in all slots except slots
J103 and J106, jumpers must be installed on the BG and IACK pins
associated with those slots. (The pins that must be jumpered are the
ones located immediately to the left of the module slot, J4 through
J14, depending on the slot, when viewed from the rear of the
backplane.) In this case, the following pairs of header pins would
require jumpers:
