USB2513B-AEZC View Datasheet(PDF) - SMSC -> Microchip
Part Name
Description
MFG CO.
'USB2513B-AEZC' PDF : 63 Pages View PDF
USB 2.0 Hi-Speed Hub Controller
Datasheet
5.3.2.1
Block Write/Read
The block write begins with a slave address and a write condition. After the command code, the host
issues a byte count which describes how many more bytes will follow in the message. If a slave had
20 bytes to send, the first byte would be the number 20 (14h), followed by the 20 bytes of data. The
byte count may not be zero. A block write or read allows a transfer maximum of 32 data bytes.
Note: For the following SMBus tables:
Denotes Master-to-Slave
Denotes Slave-to-Master
1
7
11
8
1
S
Slave Address
Wr A Register Address A ...
8
1
8
1
8
1
Byte Count = N A Data byte 1 A Data byte 2 A
8
11
Data byte N A P
5.3.2.2
Figure 5.1 Block Write
Block Read
A block read differs from a block write in that the repeated start condition exists to satisfy the I2C
specification’s requirement for a change in the transfer direction.
1
7
11
8
1
S Slave Address Wr A Register Address A
1
7
11
S Slave Address Rd A ...
8
1
8
1
8
1
Byte Count = N A Data byte 1 A Data byte 2 A
8
11
Data byte N A P
5.3.2.3
5.3.3
Figure 5.2 Block Read
Invalid Protocol Response Behavior
Note that any attempt to update registers with an invalid protocol will not be updated. The only valid
protocols are write block and read block (described above), where the hub only responds to the 7-bit
hardware selected slave address (0101100b). Also, the only valid registers for the hub are outlined in
Section 5.1 on page 27. Attempts to access any other registers will return no response.
Slave Device Timeout
Devices in a transfer can abort the transfer in progress and release the bus when any single clock low
interval exceeds 25 ms (TTIMEOUT, MIN). The master must detect this condition and generate a stop
condition within or after the transfer of the interrupted data byte. Slave devices must reset their
communication and be able to receive a new START condition no later than 35 ms (TTIMEOUT, MAX).
Note: Some simple devices do not contain a clock low drive circuit; this simple kind of device typically
resets its communications port after a start or stop condition. The slave device timeout must
be implemented.
SMSC USB251xB/xBi
43
DATASHEET
Revision 2.2 (02-17-12)
Share Link: 
