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Receive List Format
5-8
Table 5–1. Receive Parameter List Fields
Field Definition
Forward pointer This full 32-bit field contains a pointer to the next receive parameter list in the chain. The
three LSBs of this field are ignored, as lists must always be on an eight-byte address
boundary. When the pointer is 0, the current receive parameter list is the last in the chain.
The adapter processes receive parameter lists until it reads a list with a 0 forward pointer.
When a valid frame has been received into the data area pointed to by this list and the
receive CSTAT complete field is written, the receive channel stops. An Rx EOC interrupt
is raised for the channel, but this is seen by the host (because of interrupt prioritization)
until all outstanding Rx EOF interrupts have been acknowledged.
The system must update the forward pointer as a single 32-bit write operation to ensure
the adapter does not read it during update.
The adapter does not alter this field.
Receive CSTAT This 16-bit parameter is written to by the host when the receive parameter list is created.
It is overwritten by the adapter to report frame completion status. When initially written
to by the host, this field is referred to as the receive CSTAT request field.
After a frame finishes receiving, the adapter overwrites this field and it is referred to as
the receive CSTAT complete field. This indicates completion of frame reception, not
completion of the receive command.
The bit definitions for these two fields are contained in later tables.
Frame size This 16-bit field contains the number of bytes in the received frame. This field is written
by the adapter after frame reception. The frame size value does not include any frame
delimiters, preambles, postscripts, or CRC fields (except in pass_CRC mode). The
adapter ignores the initial value of this field.
Data count This 32-bit field indicates the maximum number of frame data bytes to be stored at the
address indicated by the following data address field. There can be up to ten data count/
data address parameters in a list.
A data count of 0 is necessary in the next data count field of the list if you are in multifrag-
ment mode and are using less than nine fragments.
Data address
This 32-bit field contains a pointer to a fragment (or all) of the frame data storage in host
(PCI) address space. Data address is a full-byte address. Frame fragments can start
(and end) on any byte boundary.