mcs7860 MosChip, mcs7860 Datasheet - Page 6

• Manufacturer Part Number: mcs7860
• Description: Usb 2.0 Link Controller With Phy
• Manufacturer: MosChip

MCS7860
USB 2.0 Link Controller with PHY
DEVICE OPERATION
This device consists of three sections, two USB device
controllers along with transceivers and a ‘bridge sec-
tion’ with internal buffers.
The USB device controller supports four endpoints (con-
trol, bulk_in, bulk_out and interrupt_in end points). The
‘bridge’ has the following data-flow paths.
Data flow from USB A to USB B or USB B to USB A.
The data flow can also be simultanious. The USB A to
USB B path uses bulk_out endpoint of USB A to send
data from USB A device controller to the USB B device
controller through the ‘bridge’.
Similarly The USB B to USB A path uses bulk_out end-
point of USB B to send data from USB B device con-
troller to the USB A device controller through the ‘bridge’.
There are two sets of 16-bit interrupt registers. They
reflect current status of the device and the transaction.
These bits are set/cleared through vendor specific com-
mands. The current status is reported to the correspond-
ing USB host through interrupt endpoint.
Control path used for the configuration of the device
and for processing the vendor specific commands.
Interface
The device-controller works on UTMI based interface
to the USB 2.0 PHY on the host side. The application
side of the device-controller has got a generic interface
consisting of data-bus, the endpoint_select and
read_valid, write_valid and error signals.
Functions
Functionally the device-controller has 10 parts.
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1. Mode Selector
Performs the functions of selecting speed and imple-
ments USB defined test modes. Performs the sus-
pend/resume operations.
2. Serial Interface Engine.
SIE implements the first stage decoding of the re-
ceived packets. It checks for the address and valid
endpoint numbers. It also checks for the PID errors
and CRC errors. It then enables appropriate end-
point to process the further stages of the transfer. It
also performs the functions required for packet trans-
mits.
3. Standard Command Processor.
It processes the standard USB commands. Decodes
the commands and generates the control signals to
descriptors’ block device_state_machine and end-
points.
4. Device State Machine.
5. Descriptors Block.
It consists of registers set that stores descriptor-da-
tabase. It also has the logic to read /write these reg-
isters.
6. Control Endpoint.
Implements the logic for flow of control commands.
7. Bulk_out Endpoint.
Implements the functions to control data flow from
USB-HOST to the USB-device.
8. Bulk_in Endpoint.
Implements the functions to control data flow from
USB-device to the USB-host.
9. Interrupt Endpoint.
The USB-host accesses this endpoint periodically
to read the status of the device. This endpoint
implements the functions to control the status flow
from USB-device to the USB-host.
10. Advanced Command Processor.
It processes the vendor specific commands.
Rev. 1.2