TC1796
System Units (Vol. 1 of 2)
Data Memory Unit
User’s Manual
8-1
V2.0, 2007-07
DMU, V2.0
8
Data Memory Unit
The Data Memory Unit (DMU) shown in
contains a total of 80 Kbyte of fast
static RAM memory:
•
64 Kbyte SRAM memory that can be used as
– Normal data storage
– Overlay memory
– Data Flash mirror memory
•
16 Kbyte of standby memory (SBRAM)
•
SRAM and SBRAM are parity protected
•
With overlay address generation and control logic, that makes it possible to redirect
data accesses to the PMU-based memories into the DMU or emulation memory.
Figure 8-1
Block Diagram of the Data Memory Unit (DMU)
Note: DMU memories cannot be accessed by the PCP using burst transfers (BCOPY
instruction).
DMU
MCB05648
DMU
Control
Overlay Address
Generation &
Control
SRAM
64 KB
SBRAM
16 KB
To/From Data
Local Memory Bus
DLMB Interface
Slave
Master
To
Program
Local
Memory
Bus
SRAM
= Data Memory
DFSRAM = Data Flash shadow RAM
OVRAM
= RAM with overlay capability
SBRAM
= Stand-by RAM
V
DD
Sl
av
e
Ma
s
te
r
64
64
64
64
PL
MB
(L
MI)
I
n
ter
fa
c
e
V
DDRAM
V
DDSBRAM
Parity
Control/Check
To SCU
(DMU Memory Parity Error)