MA31751 Datasheet, PDF (3/17 Pages) Dynex Semiconductor – Memory Management & Block Protection Unit

MA31751
MPROEN
Protect logic
Extended
Address
Address
Access
violation
Execute
protect
Lock and key
access protection
Write
protect
4
AL E RES* PPA
4
AL W RES* PPA
3 bits 8 bits
8/11-bit address
expansion
1750B
3
8
12 bits
12-bit logical
address
12
W RES
Instruction
PPAAL ^{E RES* PPA}
PPAAL ^{W RES* PPA}
Page Register
Operand
DMA
PS
DMAKN
AS
32
groups
5
Group address
PS
AS
OIN
from CPU status word
AL _{W RES PPA}
Page Register
AL W RES* PPA
0 3 4 5 7 8 15
* These 3 bits are reserved in 1750A. In 1750B they are used as
extra PPA bits to form the MSB's of the extended address bus.
LPA 12 LSB of Address ^{16-bit logical}
4
address
16
words
Address of
word within
4k page
Logical
Address of
4k page
Figure 3: MMU Memory Mapping Mechanism
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