Rev. 1.10
15 of 20
August 12, 2020
HT32 MCU
Starter Kit User Manual
3 Connection between the e-Link32 Lite and the T
arget Board
4 Schematics
The diagrams above are the schematic diagram of the connection between the e-Link32 Lite and
the Target Board:
▆
The e-Link32 Lite currently uses three hardware versions which are V2.0, V2.2 and V2.3.
Because V2.2 and V2.3 are roughly the same, only V2.3 is listed here. The detailed schematic
diagram will be attached to the schematic section for reference.
▆
The U4, U5 and U6 level shifter ICs are responsible for converting the SWDIO and SWCLK pin
voltage levels to the Target MCU voltage level.
When J8 or R8 is selected to be open circuit, CN2-1 is used as an input and the e-Link32 Lite is
separated, the reference voltage must be supplied on CN2-1.
▆
J8 or R8 can determine whether VDD_elink32 and CN2-1 are connected together. If they are
connected together, the SWDIO and SWCLK pin higher levels are fixed at 3.3V. At the same
time CN2-1 has the ability to output 3.3V, which can be supplied to the user’s own board.
Here it should be noted that if the user’s own board contains a power supply, then CN2-1 cannot
be connected to the user’s own board, otherwise it may cause a power conflict.
▆
CN2 and CN6 are the SWD connectors of the e-Link32 Lite and the Target Board respectively.
●
If the e-Link32 Lite is not separated, there is already a PCB line connection on the board, so
switching S1 to the ON position can connect the Target Board without an additional flying
line connection.
●
If the e-Link32 Lite is not separated and S1 is switched to the OFF position, CN2 can be
connected to the user’s own board through a flying line.
●
When the e-Link32 Lite is separated, CN2 can be connected to the Target Board CN6 or the
user’s own board through a flying line.
▆
The e-Link32 Lite has an integrated USB to UART function which is called the “Virtual COM
Port”, CN8 is its UART side connector.
●
If the e-Link32 Lite is not separated, users can use the e-Link32 “Virtual COM Port” functions
by connecting J2 to DAP_TX.
●
If the e-Link32 Lite is not separated, and users wish to connect the e-Link32 RX to their
board, they need to erase the Target MCU of the Starter Kit to avoid conflict.
●
When the e-Link32 Lite is separated, CN8 can be connected to the Target Board or the user’s
own board through a flying line.
4
4
Schematics
This section shows the HT32 MCU Starter Kit circuit diagrams:
▆
e-Link32 Lite V2.0
▆
e-Link32 Lite V2.2
▆
e-Link32 Lite V2.3
▆
HT32F52352 Target Board – ESK32-30501
Other Starter Kit target board circuit diagrams can be downloaded on Holtek official website.