6300ESB Datasheet, PDF (211/848 Pages) Intel Corporation – I/O Controller Hub

5—Intel^® 6300ESB ICH
The function address (ADDR) field specifies the function, through its address, that is
either the source or destination of a data packet, depending on the value of the token
PID. As shown in Table 99, a total of 128 addresses are specified as ADDR[6:0]. The
ADDR field is specified for IN, SETUP, and OUT tokens.
Endpoint Field
An additional four-bit endpoint (ENDP) field, shown in Table 100, permits more flexible
addressing of functions in which more than one sub-channel is required. Endpoint
numbers are function specific. The endpoint field is defined for IN, SETUP, and OUT
token PIDs only.
Table 100. Endpoint Field
Bit
Data Sent
0
ENDP 0
1
ENDP 1
2
ENDP 2
3
ENDP 3
5.17.5.5 Frame Number Field
The frame number field is an 11-bit field that is incremented by the host on a per frame
basis. The frame number field rolls over upon reaching its maximum value of x7FF, and
is sent only for SOF tokens at the start of each frame.
5.17.5.6 Data Field
The data field may range from zero to 1023 bytes and must be an integral numbers of
bytes. Data bits within each byte are shifted out LSB first.
5.17.5.7 Cyclic Redundancy Check (CRC)
CRC is used to protect the all non-PID fields in token and data packets. In this context,
these fields are considered to be protected fields. The PID is not included in the CRC
check of a packet containing CRC. All CRCs are generated over their respective fields in
the transmitter before bit stuffing is performed. Similarly, CRCs are decoded in the
receiver after stuffed bits have been removed. Token and data packet CRCs provide
100% coverage for all single and double bit errors. A failed CRC is considered to
indicate that one or more of the protected fields is corrupted and causes the receiver to
ignore those fields, and, in most cases, the entire packet.
5.17.6 Packet Formats
5.17.6.1 Token Packets
Table 101 shows the field formats for a token packet. A token consists of a PID,
specifying either IN, OUT, or SETUP packet type, and ADDR and ENDP fields. For OUT
and SETUP transactions, the address and endpoint fields uniquely identify the endpoint
that will receive the subsequent data packet. For IN transactions, these fields uniquely
identify which endpoint should transmit a data packet. Only the Intel^® 6300ESB ICH
may issue token packets. IN PIDs define a data transaction from a function to the
Intel^® 6300ESB ICH. OUT and SETUP PIDs define data transactions from the Intel^®
6300ESB ICH to a function.
November 2007
Order Number: 300641-004US
Intel^® 6300ESB I/O Controller Hub
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