Renesas L78/G1A, User Manual

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E1/E20/E2/E2 Lite Additional Document 2. Designing the User System
R20UT1994EJ0900 Rev.9.00 Page 25 of 58
Jan.20.22
2.5 Notes on Connection
Wiring patterns between the connector and the MCU must be as short as possible (within 50 mm is
recommended). Do not connect the signal lines between the connector and MCU to other signal lines on the
board.
For the handling of pins while the E1/E20/E2/E2 Lite is not in use, refer to the hardware manual for the MCU.
2.5.1 RESET# Pin
The RESET# pin is used by the E1/E20/E2/E2 Lite to monitor the pin state and issue a reset to the device.
Therefore, a reset signal on the user system is once input to the E1/E20/E2/E2 Lite where it is controlled by
masking and then output to the target device. Connection examples of the RESET# pin section are shown in
Table 2-3 and Figure 2-9 to Figure 2-14.
When flash programming by the programming software is to be performed, the RESET# pin should be
designed so that the reset signal on the user system does not conflict with the reset signal from the
E1/E20/E2/E2 Lite.
When you use hot plug-in, install a ceramic capacitor (approx. 0.1 µF) between the RESET# pin and GND in
order to suppress a noise to the RESET# pin that would occur when the emulator is connected.
Hot plug-ins are not available if there is no reset circuit.
Table 2-3 Connection Examples According to the Reset Circuit on the User System
No. Target Device Case Reference
1 RL78 family MCUs
in general There is a reset circuit on the user system.
(Resistors are used to switch between usage and non-usage
of the emulator.)
Figure 2-9
2 There is a reset circuit on the user system.
(A jumper is used to switch between usage and non-usage of
the emulator.)
Figure 2-10
3 The power-on reset circuit is the only reset circuit on the user
system. Figure 2-11
4 RL78/G11,
20- and 24-pin
versions of the
RL78/G12
The pin on which the RESET# function is multiplexed is in
use for the reset function.
There is no reset circuit if the section enclosed by the dotted
lines described in note 2 for figure 2-12 is removed.
Figure 2-12
The pin on which the RESET# function is multiplexed is in
use for another function.
(when using the P125/KR1/SI01 function which is multiplexed
with RESET#)
Figure 2-13
5 RL78/I1C The battery backup function is not in use.
There is no reset circuit if the section enclosed by the dotted
lines described in note 2 for figure 2-12 is removed.
Figure 2-12
6 The battery backup function is in use.
There is no reset circuit if the section enclosed by the dotted
lines described in note 2 for figure 2-14 is removed.
Figure 2-14