DEC AlphaServer 8200 Technical Manual page 252

Table 7-15 Mailbox Data Structure Description (Continued)
QW Bit(s) Name
<63:0> RDATA
4
<0> DON
5
<1> ERR
<63:2> STATUS
7-34 System Registers
Description
Read Data. For read commands, contains the data returned.
For write data commands, the field is Unpredictable.
Done. For read commands, indicates that the <ERR>,
<STATUS>, and <RDATA> fields are valid. For all commands,
indicates that the mailbox structure may be safely modified by
host software.
Error. If set on a read command, indicates that an error was
encountered. Valid only on read commands and when <DON>
is set. This field is Unpredictable on write commands. See Al-
pha SRM.
Operation Completion Status. Contains information specific
to the bridge implementation. Valid only on read commands
and when <DON> is set. This field is Unpredictable on write
commands.