TC1796
System Units (Vol. 1 of 2)
Data Memory Unit
User’s Manual
8-13
V2.0, 2007-07
DMU, V2.0
For each of the 16 overlay sections (indicated by index x), three registers control the
overlay operation:
•
The Redirected Address Base Register RABRx, which holds the base address of the
overlay memory block in the overlay memory, and some control bits
•
The Overlay Target Address Register OTARx, which holds the base address of the
memory block being overlayed
•
The Overlay Mask Register OMASKx, which determines which bits are part of the
offset address and which bits are part of the base address
0
[31:8]
r
Reserved
Read as 0; should be written with 0.
RABRx (x = 0-15)
Redirected Address Base Register x
(20
H
+x*C
H
)
Reset Value: 0000 0000
H
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
OV
EN
IEMS
= 0
RC1 RC0
0
rw
r
r
r
r
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
OBASE
0
rw
r
Field
Bits
Type Description
OBASE
[15:1]
rw
Overlay Base Address
This bit field holds the base address of the overlay
memory block in the overlay memory.
The largest block base address that is allowed, is
(OBASE
max
- block size
1)
)
RC0
RC1
28,
29
r
Reserved Control Bits
These bits are reserved for future control expansions.
Read returns 0. Bits should be written with 0.
Field
Bits
Type Description