Brother P-Touch QL-570 - Reset Circuit; USB Interface Circuit

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2.3.8 Reset Circuit
When power is supplied from the power supply PCB, +3.3V is supplied, and power is supplied to
the CPU. At this point, if +3.3V voltage line goes over +2.8V, the reset circuit (U5) sets High to the
RESET input (14 pins) of the CPU, clearing the RESET status of the CPU.
If the +3.3V voltage line drop to +2.8V or lower due to any reason during operation, the reset
circuits returns Low signal to the CPU and the CPU goes to the RESET status.
Fig. 2.3-10 Reset Circuit
2.3.9 USB Interface Circuit
The CPU of QL-570 is connected with a PC using the USB cable via U6 and CN12.
U6 and CPU (U7) establishes bus connection with 8-bits.
Fig. 2.3-11 USB Interface Circuit