User`s guide

DWMBB/A Module Registers
Bus Error Register (XBER)
bit<15>
Name: Command NO ACK
Mnemonic: CNAK
Type: R/W1C, 0
When set, CNAK indicates that a command/address cycle transmitted
by the DWMBB received a NO ACK confirmation and all reattempts
have failed (retry timeout). This can be caused by either a reference to
a nonexistent memory location or a command cycle parity error. This
bit is set only if all retries fail and TTO sets.
bit<14>
Name: Reserved
Mnemonic: None
Type: RO, 0
Reserved; must be zero.
bit<13>
Name: Transaction Timeout
Mnemonic: TTO
Type: R/W1C, 0
When set, TTO indicates that one of the following has occurred:
• The DWMBB did not receive an XMI grant before the timeout limit
was reached.
• The DWMBB received a NO ACK response to a C/A cycle and all
reattempts have failed (CNAK bit).
• The DWMBB did not receive read data in response to an ACKed
read command before the timeout limit was reached (NRR bit).
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