SPI Programming Manual (G06.24+, H06.03+, J06.03+)

SPI Concepts and Protocol
SPI Programming Manual—427506-006
2-40
Segmented Responses
Determining Subsystem Support for Segmented Responses
A subsystem that returns ZSPI-TKN-SEGMENTATION with a value of TRUE in its
GETVERSION response can generate segmented responses.
A subsystem that supports segmentation for any command must support segmentation
for all commands.
Requesting a Segmented Response
To request a segmented response, a command must include ZSPI-TKN-ALLOW with
the value ZSPI-VAL-ALLOW-SEGMENTS. Otherwise, segmentation is disallowed. A
requester must allow or disallow segmented responses for each command it issues.
The default is to disallow segmented responses.
Table 2-2
summarizes possible subsystem responses to a request to allow or disallow
segmentation. Response varies, depending on the content of the request and the
subsystem’s level of support for segmented responses.
Table 2-2. Subsystem Response to Requests for Segmented Responses
Does the
command contain
ZSPI-TKN-ALLOW with
value ZSPI-VAL-
ALLOW-SEGMENTS?
If subsystem
supports
segmentation…
If subsystem
does not support
segmentation…
If subsystem
requires requester
to accept
segmented
responses…
Yes The subsystem
returns a
segmented
response.
The subsystem
returns an “invalid
token” error after
finding ZSPI-TKN-
ALLOW with value
ZSPI-VAL-ALLOW-
SEGMENTS.
The subsystem
returns a segmented
response.
No The subsystem
returns a
response record
that is truncated if
it does not fit in
the buffer.
The subsystem
returns a response
record that is
truncated if it does
not fit in the buffer.
The subsystem
returns
ZSPI-ERR-MISTKN
after failing to find
ZSPI-TKN-ALLOW
with value ZSPI-VAL-
ALLOW-SEGMENTS.