E2/E2 Lite
R20UT4582EJ0100 Rev.1.00
Page 12 of 30
Jul.16.19
2.4
Recommended Circuit between the Connector and the MCU
This section shows recommended circuits for connection between the connector and the MCU when the
E2/E2 Lite is used. For details on the handling of signals, refer to section 2.5, Notes on Connection.
2.4.1
SWD Interface Connection between the 20-Pin and 10-Pin Connectors and the MCU
Figure 2.3 shows a recommended circuit for connection between the 20-pin and 10-pin connectors and the
MCU in SWD interface connection.
Open-collector
buffer*
2
SWCLK/TxD9
SWDIO/RxD9
VCC
Reset
circuit
20-pin and 10-pin
1.27-mm pitch
connector
VCC
SWCLK/RxD
SWDIO/TxD
RES#
GND
Pull up at
4.7 k
Ω
to 10 k
Ω
3, 5, 9,
15, 17, 19*
1
10
4
1
RES#
VCC
Not
connected
6, 7, 8,
11, 12, 13, 14, 16, 18, 20*
1
MCU
VCC
VCC
2
Figure 2.3 Example of Connection between the 20-Pin and 10-Pin Connectors and the MCU in SWD
Interface Connection
Notes:
1.
If a 10-pin (1.27-mm pin pitch) connector is mounted on the user system, pins 11 to 20 are
not used.
2.
The output of the reset circuit of the user system must be open collector.
3.
Since the E2 Lite does not support the SCI, it does not allow the programming of flash
memory with the use of programming software.
4.
The MD pin can operate even if it is not connected to the E2/E2 Lite. When the pin is not
connected to the E2/E2 Lite, a special circuit for the pin must be configured on the user
system. For details on the handling of the MD pin, refer to section 2.5, Notes on Connection.
