Motorola MVME956AC, MVME956UM2 user manual Install the Daisy-Chain Jumpers

Install the Daisy-Chain Jumpers

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:

4

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