Backplane Jtag Buffer Enable Link (P4 3-4); Backplane Jtag Auto-Write Enable Link (P4 5-6); Force 33 Mhz Operation Link (P5 1-2); Table 2-8 Link P4 3-4 - GE IMP2B Hardware Reference Manual

2.9 Backplane JTAG Buffer Enable Link (P4 3-4)

This link allows the JTAG Scanbridge to be driven from the backplane signals as
allocated by PICMG 2.0, Rev 3.0.

Table 2-8 Link P4 3-4

Link
Out
In

2.10 Backplane JTAG Auto-Write Enable Link (P4 5-6)

This link connects the AutoWrite signal (as used by the JTAG Technologies Flash
Programming equipment) from the backplane to the JTAG Scanbridge device.

Table 2-9 Link P4 5-6

Link
Out
In

2.11 Force 33 MHz Operation Link (P5 1-2)

The IMP2B is compatible with both 33 MHz and 66 MHz CompactPCI backplane
speeds. This link forces the CompactPCI backplane to operate at 33 MHz, even if the
system is capable of operating at 66 MHz. The CompactPCI bus speed can be read
from the EPLD

Table 2-10 Link P5 1-2

Link
Out
In
14 IMP2B 3U cPCI Single Board Computer
Function
Backplane JTAG signals disabled
Backplane JTAG signals enabled
NOTE
In PICMG 2.0, Rev 3.0, it is recommended that the backplane JTAG signals are not used. When this link
is out, the IMP2B does not drive these pins and so these signals may be used for any other purpose
allocated to them.
Function
Backplane JTAG AutoWrite signal not connected
Backplane JTAG AutoWrite signal connected
NOTE
The AutoWrite signal is allocated to a bused-reserved pin (A5) on
signal to be disconnected if this pin is not being used for this purpose.
Device/Bus Information Register
Function
CompactPCI backplane speed defined by system
CompactPCI backplane forced to 33 MHz
connector J1. This link allows the
1.
Publication No. IMP2B-0HH/5