48
6174B–ATARM–07-Nov-05
AT91FR40162S Preliminary
10.11.3
EBI Memory Control Register
Register Name:
EBI_MCR
Access Type:
Read/Write
Reset Value:
0
Absolute Address:
0xFFE00024
Offset:
0x24
• ALE: Address Line Enable
This field determines the number of valid address lines and the number of valid chip select lines.
• DRP: Data Read Protocol
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
–
15
14
13
12
11
10
9
8
–
–
–
–
–
–
–
–
7
6
5
4
3
2
1
0
–
–
–
DRP
–
ALE
ALE
Valid Address Bits
Maximum Addressable Space
Valid Chip Select
Code Label
EBI_ALE
0
X
X
A20, A21, A22, A23
16M Bytes
None
EBI_ALE_16M
1
0
0
A20, A21, A22
8M Bytes
CS4
EBI_ALE_8M
1
0
1
A20, A21
4M Bytes
CS4, CS5
EBI_ALE_4M
1
1
0
A20
2M Bytes
CS4, CS5, CS6
EBI_ALE_2M
1
1
1
None
1M Byte
CS4, CS5, CS6, CS7
EBI_ALE_1M
DRP
Selected DRP
Code Label
EBI_DRP
0
Standard read protocol for all external memory devices enabled
EBI_DRP_STANDARD
1
Early read protocol for all external memory devices enabled
EBI_DRP_EARLY