mcs7860 MosChip, mcs7860 Datasheet - Page 11

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

WRSM
It interfaces the USB device controller’s bulk out end-
point to the bridge. It receives data from USB with a
maximum packet size of 512 bytes in High speed (64
bytes in Full speed), per transaction and writes to the
SRAM. It works under the control of bulk_out_endpoint
of the usb_device_controller. The bridge memory seg-
ment has got two banks of memory for data flow in each
direction. The WRSM keeps track of the bank to be
written.
It keeps track of the write pointer, generates write ad-
dresses and other signals for write operation to the
memory. It also updates the ready for write flags for
each of the banks.
Commands:
This device supports nine standard USB commands
and three two vendor specific commands. They are as
follows.
The format of the standard commands is as per the
USB Specification.
Rev. 1.2
bmRequestType
USB Standard Commands:
1.
2.
3.
4.
5.
6.
7.
8.
9.
0100_0000
SET ADDRESS.
CLEAR FEATURE.
GET STATUS.
GET CONFIGURATION.
SET CONFIGURATION.
GET DESCRIPTOR.
SET FEATURE.
GET INTERFACE.
SET INTERFACE.
0000_1101
bRequest
Feature Selector
wValue
It generates the busy/ready signal to the
bulk_out_endpoint
usb_device_controller to generate appropriate ACK/
NAK/NYET handshake to the host.
If the bulk_out_endpoint reports packet error, the WRSM
flushes the memory banks by moving write_pointers
back to their initial value (initial value of the write_pointer
is the value in this register before the start of this trans-
fer).
At the end of a transfer, control information is loaded
into the last location (Location 257) of the FIFO.
Vendor Specific Commands:
Set_Link_Feature.
Vendor specific command to set the bits in the interrupt
register.
Value field is the value of the feature to be set. wLength
and wIndex should be “0”. If the wValue field is non zero,
the value and the feature selector specified in the wValue
field are invalid and the device responds with a “STALL”
handshake.
USB 2.0 Link Controller with PHY
Value
1
2
3
4
5
Feature
P_En
T_Request
T_Com
RES_In
RES_Out
wIndex
0000
MCS7860
so
as
to
wLength
0000
enable
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