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The evaluation board is CH376S chip, but in some signal is CH375 or CH374 name

Crystals X1 as the standard 12MHz, USB host than USB equipment required frequency accuracy higher, X1 error is less than 0.4 ‰, 12MHz crystal can basically meet the requirements of general. Strongly recommended to shorten the lead length, to reduce interference

Capacitor C4 is used for internal power supply node decoupled to reduce USB transmission process of EMI, the capacity is 4700pF to 0.1uF, you can choose ordinary 103 SMD capacitors 0.01uF

P4 is USB port, which can be used for USB HOST mode, it can also be used for USB DEVICE devices, R1 for the current limit resistor output to external USB device, avoid the short time caused by power supply voltage in the U plate, USB equipment was inserted decline, and even cause CH376 or SCM abnormal reset or internal RAM data error. If it is a USB drive, it should be changed into the inductor resistance R1 DC resistance is small, or by a group of 5V power supply directly provide more current (above 500mA) to an external hard disk. In addition, the power supply socket USB-HOST decoupling capacitor C9 capacity can not be too small, large capacity (should be larger than 100 μ F) can reduce the supply voltage in the USB equipment is just inserted when fluctuation.

P5 is SD card socket, can reach the standard size of the SD card, the other specifications of the SD card can need additional conversion base. For the current limiting resistor R3 is output to the external SD card, avoid the short time caused by power supply voltage in SD Kagan is inserted down.

P1 is 8 bit parallel port used to connect the signal, single chip microcomputer parallel port, the necessary signal parallel including D0-D7, A0, RD#, WR#, CS# and GND, but the INT# is optional.

P2 is signal port SPI serial port, SPI interface used to connect the chip, the necessary signal SPI including SCS, SCK, SDI, SDO and GND, but the INT# is optional.

P3 is signal port asynchronous serial port asynchronous serial port, used for connecting one of the microcontroller, the necessary signal asynchronous serial interface including RXD, TXD and GND, but the INT# is optional. P3 also provides the write protect SDWP and plug the SDINSERT signal line SD card.

P1, P2, P3 communication port, can also provide 5V power from the outside to the evaluation board, as well as to the CH376 RSTI pin provides a hardware reset signal is optional, if μ P monitoring circuit actual product circuit, it shall be provided with a reset signal for the CH376 and single chip microcomputer. Pay attention to, should try to shorten the signal line between the board and the evaluation of single length, the length of not more than 20cm, special cable or requires the use of a signal at intervals of one wire.

J3 is used to select the CH376 chip voltage, short circuit 1-2 feet for the 5V voltage, short circuit to 3.3V voltage 2-3 pin. The default for 5V voltage, when the voltage is equal to or lower than the single chip 3.3V, can choose 3.3V voltage CH376. Working voltage when the CH376 chip 5V, J2 must be disconnected, the working voltage when the CH376 chip 3.3V, J2 must be short circuited.

J1, J5 and J6 is used to select the communication interface of CH376 and single-chip microcomputer in hardware reset power on or after:
If the J1 short connection, J5 off, J6 off, so is a 8 bit parallel port;
If the J1 is disconnected, J5 shortened, J6 shortened, so is the SPI interface;
If the J1 off, J5 off, J6 off, so is the asynchronous serial port.

Some examples of procedures may be debugging information using the serial output, if the need to display the monitoring information, can be the serial after RS232 level conversion and connected to a computer using a serial port monitoring / debugging tools to view. If you use the CH375 evaluation board, so J2 can be connected to the serial port of the computer; if the computer is not serial, or serial port has been occupied by other devices, you can USB to serial chip CH341 serial port emulation.

CH375 evaluation board of internal components in supply voltage is 5V, must add the resistance R0 and remove the 3.3V regulator D4, works in the 3.3V power voltage regulator D4, must add and remove resistance R0. The default is 5V power supply