TC1796
System Units (Vol. 1 of 2)
LMB External Bus Unit
User’s Manual
13-90
V2.0, 2007-07
EBU, V2.0
13.10.5
Address Select Register, ADDRSELx
EBU_ADDRSELx (x = 0-3)
EBU Address Select Register x
(080
H
+x*8
H
)
ADDRSEL[3:1] - Reset Value: 0000 0000
H
ADDRSEL0 - Reset Value (internal boot): 0000 0000
H
ADDRSEL0 - Reset Value (external boot): A000 0001
H
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
BASE
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
BASE
ALTSEG
MASK
0
ALT
EN
AB
REG
EN
AB
rw
rw
rw
r
rw
rw
Field
Bits
Type Description
REGENAB
0
rw
Memory Region Enable
0
B
Memory region is disabled (default after reset
except for ADDRSEL0 - see below).
1
B
Memory region is enabled.
When the EBU is in external boot mode, REGENAB
in register ADDRSEL0 is 1 after reset.
ALTENAB
1
rw
Alternate Segment Comparison Enable
0
B
ALTSEG is never compared to LMB address
(default after reset).
1
B
ALTSEG is always compared to LMB address.
MASK
[7:4]
rw
Memory Region Address Mask
Specifies the number of right-most bits in the base
address starting at bit 26, which should be included in
the address comparison. Bits [31:27] will always be
part of the comparison.
ALTSEG
[11:8]
rw
Memory Region Alternate Segment
Alternate segment to be compared to PLMB address
bit [31:28].