Compaq 21264 - Manual (Page 229)

Alpha 21264/EV67 Hardware Reference Manual Error Detection and Error Handling 8–1
8
Error Detection and Error Handling
This chapter gives an overview of the 21264/EV67 error detection and error handling
mechanisms, and is organized as follows:
• Data error correction code
• Icache data or tag parity error
• Dcache tag parity error
• Dcache data correctable ECC error
• Dcache store second error
• Dcache duplicate tag parity error
• Bcache tag parity error
• Bcache data correctable ECC error
• Memory/system port data correctable ECC error
• Bcache data correctable ECC error on a probe
• Double-bit fill errors
• Error case summary
Table 8–1 summarizes the 21264/EV67 error detection.
Table 8–1 21264/EV67 Error Detection Mechanisms
Component Error Detection Mechanism
Bcache tag Parity protected.
Bcache data array Quadword-ECC protected.
Dcache tag array Parity protected.
Dcache duplicate tag array Parity protected.
Dcache data array Quadword-ECC protected, however this mode of operation is
only supported in systems that have ECC enabled on both the
system and Bcache ports.
Icache tag array Parity protected.
Icache data array Parity protected.
System port data bus Quadword-ECC protected.