EP2AGX95EF29C6N Datasheet, PDF (57/380 Pages) Altera Corporation – Device Interfaces and Integration

Chapter 3: Memory Blocks in Arria II Devices
3–9
Memory Features
Table 3–3 lists the truth table for the ECC status flags.
Table 3–3. Truth Table for ECC Status Flags in Arria II Devices
Status
No error
Single error and fixed
Double error and no fix
Illegal
Illegal
Illegal
Illegal
eccstatus[2]
0
0
1
0
0
1
1
eccstatus[1]
0
1
0
0
1
0
1
eccstatus[0]
0
1
1
1
0
0
X
1 You cannot use the byte enable feature when ECC is engaged.
1 Read-during-write old data mode is not supported when ECC is engaged.
Figure 3–8 shows a diagram of the ECC block of the M144K block.
Figure 3–8. ECC Block Diagram of the M144K Block
8
64
Data Input
64
SECDED ⁸
Encoder
64
72
RAM
72
Array
64 _SECDED
Encoder ₈
Comparator
8
64
Error
Locator
64
Error
Correction
Block
64
88
Flag
Generator
3
Status Flags
Data Output
December 2011 Altera Corporation
Arria II Device Handbook Volume 1: Device Interfaces and Integration