mcs7715 MosChip, mcs7715 Datasheet - Page 6

• Manufacturer Part Number: mcs7715
• Description: Usb 1.1 To Single Uart And Printer Port
• Manufacturer: MosChip

MCS7715
USB 1.1 to Single UART and Printer Port
USB Description
Analog Transceivers
The on-chip transceivers are connected directly to USB cables through external series resistors. They
transmit and receive serial data at both full-speed (12Mbit/s) and low-speed (1.5Mbit/s) data rates. Slew rates
are automatically adjusted according to the speed of the device connected and lie within the range defined in
the USB Specification Rev. 1.1.
Serial Interface Engine
This engine implements the complete USB protocol layer including: parallel /serial conversion,
synchronization pattern recognition, CRC checking/generation, bit (de)stuffing, packet identifier (PID)
verification/generation, address recognition and handshake evaluation/generation.
Bit Clock Recovery
The bit clock recovery circuit recovers the clock from the incoming USB data stream using 4x over sampling.
It is able to track in the presence of jitter and frequency drift as specified by the USB Specification Rev. 1.1.
3.3V Source
A 5V to 3.3V DC-DC regulator is integral to the chip relieving the need for a +3.3V source. It supplies the
analog transceivers and internal logic and can be used to supply the 1.5kΩ pull-up resistor on the DP line of
the upstream connection.
PLL Clock Multiplier
An integral Phase-Locked Loop (PLL) performs 6 to 48MHz clock multiplication and requires no external
components except the crystal. This allows for the use of low-cost 6MHz crystals which reduce high
frequency radiated Electro-Magnetic Interference (EMI).
Rev. 1.6
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