Motorola MPC533 Reference Manual page 202

BBC Programming Model
Table 4-6. MI_RA[0:3] Registers Bit Descriptions
Bits Name
0:19 RS Region size. For byte size by region, see Table 4-7.
1
20:21 PP Protection bits:
00: Supervisor — No Access, User — No Access.
01: Supervisor — Fetch, User — No Access.
1x: Supervisor — Fetch, User — Fetch.
22:24 — Reserved
1
25 G Guard attribute for region
0 Speculative fetch is not prohibited from region. Region is not guarded.
1 Speculative fetch is prohibited from guarded region. An exception will occur under such attempt.
2
26:27 CMPR Compressed Region.
x0 The region in not restricted
01 Region is considered a non-compressed code region. Access to the region is allowed only in
11 Region is considered a compressed code region. Access to the region is allowed only in
28 BTBINH BTB Inhibit region
0 BTB operation is not prohibited for current memory region
1 BTB operation is prohibited for current memory region.
29:31 — Reserved
1
G and PP attributes perform similar protection activities on a region. The more protective attribute will be implied on the
region if the attributes programming oppose each other.
2
This bit is available only on the MPC534.
Table 4-7. Region Size Programming Possible Values
4-20
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
"Decompression Off" mode
"Decompression On" mode
RS Field Value (Binary)
0000_0000_0000_0000_0000
0000_0000_0000_0000_0001
0000_0000_0000_0000_0011
0000_0000_0000_0000_0111
0000_0000_0000_0000_1111
0000_0000_0000_0001_1111
0000_0000_0000_0011_1111
0000_0000_0000_0111_1111
0000_0000_0000_1111_1111
0000_0000_0001_1111_1111
0000_0000_0011_1111_1111
0000_0000_0111_1111_1111
0000_0000_1111_1111_1111
0000_0001_1111_1111_1111
MPC533 Reference Manual
Description
Size
4 Kbytes
8 Kbytes
16 Kbytes
32 Kbytes
64 Kbytes
128 Kbytes
256 Kbytes
512 Kbytes
1 Mbyte
2 Mbytes
4 Mbytes
8 Mbytes
16 Mbytes
32 Mbytes
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