User`s guide

DWMBB Adapter
3.12.4.3 ECC Errors on PMR Data During DMA Address Translation
The DWMBB/A module uses ECC to determine if there is an error on the
data being read from the PMR. These ECC errors can be correctable or
uncorrectable.
3.12.4.3.1 Uncorrectable ECC Errors
If an uncorrectable ECC error is detected and the DWMBB/B module does
not nullify the DMA transaction on the IBUS, the DMA Uncorrectable
ECC Error bit (AESR<9>) is set and the DWMBB:
• Aborts the DMA transaction
• Logs the ECC syndrome in ACSR<28:17>
• Logs the VAXBI address in ABEAR
• Generates an INTR if Interrupt on Uncorrectable ECC Error
(AIMR<9>) is set
• Generates an IVINTR if the DMA transaction was a write and Enable
IVINTR Transactions (AIMR<31>) is set
If the uncorrectable ECC error is detected while translating a DMA read
address, the DWMBB NO ACKs the transaction.
3.12.4.3.2 Correctable ECC Errors
If a correctable ECC error is detected on the PMR data during a DMA
address translation, the corrected PMR data is used to complete the DMA
transaction and the DWMBB performs the following:
• Sets DMA Correctable ECC Error (AESR<10>)
• Logs the ECC syndrome in ACSR<28:17>
• Logs the VAXBI address in ABEAR
• Generates an INTR if Interrupt on Correctable ECC Error (AIMR<10>)
is set
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