Figure 5 5 Hamming Example 8 bit Data

Figure 5. 5 Hamming Example – 8 bit Data (No Errors – ED[0: 12] is Encoded(d 01…d 08)) Data even parity Data odd parity (p 03=1) ED odd parity (so p. W=1) Check bits: No difference p. W 2 == p. W (as expected) Check-Bits == 0 AND p. W == p. W 2 Sam Siewert => NO ERRORS 1

Figure 5. 6 Hamming Example (Data SBE in Data ED[5]) SBE, bit-flipped (d 02 from 1 to 0) SYN encodes bit position (flip ED[5] to restore) p. W 2 != p. W (parity error) Check-Bits != 0 AND p. W != p. W 2 => SBE, CAN CORRECT Sam Siewert 2

Figure 5. 7 Hamming Example (Data MBE) MBE, 2 bits-flipped (d 02 and d 05 both) SYN encodes MBE (out of range for ECC) p. W != p. W 2 (double MBE) Check-Bits != 0 AND p. W == p. W 2 => DOUBLE MBE DETECTED Sam Siewert 3

Figure 5. 8 Hamming Example (Parity SBE in Encoded Data) SBE, bit-flipped (p 04 from 1 to 0) SYN encodes bit position (flip ED[8] to restore) p. W 2 != p. W (parity error) Check-Bits != 0 AND p. W != p. W 2 => Parity SBE, CAN CORRECT Sam Siewert 4

Figure 5. 9 Hamming Example (p. W flip – Simple Parity Error, No ED error!) SYN indicates no error (p. W flip only possibility) p. W 2 != p. W (parity error) Sam Siewert Check-Bits == 0 AND p. W != p. W 2 => p. W ERROR 5

Figure 5. 10 FS LB to PB Mapping Example #1 - Start #2 #3 #4 #5 #6 #7 #9 #10 #11 #12 #13 #14 #1 – All blocks FREE #2 – Erase S 0 & S 1, Write LB 0, 1, 2, 3 #3 – Read LB 0, 2, Modify, Write LB 0, 2 #4 – Read LB 1, 3, Modify, Write LB 1, 3 #5 – Read LB 0, 2, Modify and Cache #6 – Buffer LB 0, 1, 2, Erase S 0 #7 – Write-back LB 0, 1, 2 to S 0 11 Writes, 3 Sector Erases Write Amplification = 11 / 10 = 1. 1 #8 Start State from End State #7 Above #8 - Read LB 1, 3, Modify and Cache #9 – Erase S 1 #10 – Write-back LB 1, 3 to S 1 #11 – Read LB 0, 2, Modify, Write LB 0, 2 #12 – Read LB 1, 3, Modify and Cache #13 – Erase S 0 #14 – Write-back LB 1, 3 6 Writes, 2 Sector Erases Write Amplification = 17 / 16 = 1. 0625 Sam Siewert 6