ELM
Table 7-172. 16-bit NAND Sector Buffer Address Map
NAND
Message bit addresses in the memory word
Memory
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Address
0
4215
4214
4213
4212
4211
4210
4209
4208
4223
4222
4221
4220
4219
4218
4217
4216
1
4175
4174
4173
4172
4171
4170
4169
4168
4183
4182
4181
4180
4179
4178
4177
4176
...
47
3463
3462
3461
3460
3459
3458
3457
3456
3471
3470
3469
3468
3467
3466
3465
3464
48
3447
3446
3445
3444
3443
3442
3441
3440
3455
3454
3453
3452
3451
3450
3449
3448
49
3431
3430
3429
3428
3427
3426
3425
3424
3439
3438
3437
3436
3435
3434
3433
3432
50
3415
3414
3413
3412
3411
3410
3409
3408
3423
3422
3421
3420
3419
3418
3417
3416
...
255
135
134
133
132
131
130
129
128
143
142
141
140
139
138
137
136
256
119
118
117
116
115
114
113
112
127
126
125
124
123
122
121
120
257
103
102
101
100
99
98
97
96
111
110
109
108
107
106
105
104
258
87
86
85
84
83
82
81
80
95
94
93
92
91
90
89
88
259
71
70
69
68
67
66
65
64
79
78
77
76
75
74
73
72
260
55
54
53
52
51
50
49
48
63
62
61
60
59
58
57
56
261
39
38
37
36
35
34
33
32
47
46
45
44
43
42
41
40
262
23
22
21
20
19
18
17
16
31
30
29
28
27
26
25
24
263
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
The table can now be used to determine which bits in the buffer were incorrect and must be flipped. In this
example, the first bit to be flipped is bit 4 from the 49th byte read from memory. It is up to the processor to
correctly map this word to the copied buffer and to flip this bit. The same process must be repeated for all
detected errors.
7.4.4.3
Use Case: ELM Used in Page Mode
In this example, the ELM module is programmed for an 16-bit error-correction capability in page mode.
After reading a 528-byte NAND flash sector (512B data plus 16B spare area) with a 16-bit interface, four
non-zero polynomial syndromes are reported from the GPMC (Polynomial syndrome 0, 1, 2, and 3 are
used in the ELM):
•
P0 = 0xE8B0 12ADDB5A318E05BE B0693DB28330B5CC A329AA05E0B718EF
•
P1 = 0xBAD0 49A0D932C22E6669 0948DF08BE093336 79C6BA10E5F935EB
•
P2 = 0x69D9 B86ABCD5EC3697FA A6498FEE54556EA0 1579EF7D60BA3189
•
P3 = 0x0
Table 7-173. Use Case: Page Mode
Step
Register/ Bit Field / Programming Model
Value
Resets the module
ELM_SYSCONFIG[1] SOFTRESET
0x1
Wait until reset is done.
ELM_SYSSTATUS[0] RESETDONE
0x1
Configure the slave interface power management:
ELM_SYSCONFIG[4:3] SIDLEMODE
0x2
Smart idle is used.
Defines the error-correction level used: 16 bits
ELM_LOCATION_CONFIG[1:0] ECC_BCH_LEVEL
0x2
Defines the maximum buffer length: 528 bytes
ELM_LOCATION_CONFIG[26:16] ECC_SIZE
0x420
Sets the ELM in page mode (4 blocks in a page)
ELM_PAGE_CTRL[0] SECTOR_0
0x1
ELM_PAGE_CTRL[1] SECTOR_1
0x1
ELM_PAGE_CTRL[2] SECTOR_2
0x1
ELM_PAGE_CTRL[3] SECTOR_3
0x1
484 Memory Subsystem
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated