Connecting The System Ground - Renesas HS7125EDB01H User Manual

2.2.8

Connecting the System Ground

Separate the frame ground and signal ground of the user
system. Failure to do so will create a FIRE HAZARD that can
damage the user system and emulator product, or produce
PERSONAL INJURY.
The signal grounds of the E10A-USB emulator and the debugging MCU board are connected to
the user system's signal ground. In the emulator, the signal ground and frame ground are
connected. In the user system, only connect the frame ground to earth; do not connect the signal
ground to the frame ground (figure 2.11).
If it is difficult to separate the frame ground from the signal ground in the user system, tie the
frame ground of the user system to the same potential as the GND level of the DC power input
(AC adapter) of the host computer. This is because differences in GND potential between the host
computer and target system will lead to excessive flows of current in the low-impedance GND
lines, and thin lines might burn out.
Signal ground
E10A-USB emulator
Host
USB
computer
Power
supply
WARNING
Signal
Logic
Signal ground
Figure 2.11 Connecting System Ground
Debugging
Signal
MCU board
Signal ground
Frame ground
User system
Logic
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