Emulation Design Considerations
E-23
Design Considerations for Using XDS510 Emulator
Figure E–13. EMU0/1 Configuration With Additional AND Gate to Meet Timing
Requirements of Greater Than 25 ns
Open-
collector
drivers
EMU0/1-IN
Backplane
Target board m
TCK
XCNT_ENABLE
To Emulator EMU0
PAL
Pullup
resistor
Open-
collector
drivers
Target board 1
EMU0/1
EMU1 signal from other boards
EMU1
AND
To emulator EMU1
Circuitry required for >25-ns
rise/fall time modification
EMU0/1-OUT
. . .
Device
Device
EMU0/1
. . .
. . .
. . .
. . .
. . .
. . .
1
n
Device
Device
1
n
Up to
m boards
Pullup
resistor
Pullup
resistor
Notes:
1) The low time on EMU0/1-IN should be at least one TCK cycle and less than 10
m
s. Software will set the EMU0/1-OUT
port to a high state.
2) To enable the open-collector driver and pullup resistor on EMU1 to provide rise/fall time of greater than 25 ns, the
modification shown in this figure is suggested. Rise times of more than 25 ns can cause the emulator to detect false
edges during the RUNB command or when the external counter selected from the debugger analysis menu is used.
