DS5000FP_1 Datasheet, PDF (6/22 Pages) Dallas Semiconductor – Soft Microprocessor Chip

DS5000FP
is an identical function in a SIMM form factor. It also offers the option of a second 32k SRAM mapped
as data on Chip Enable 2.
MEMORY ORGANIZATION
Figure 2 illustrates the memory map accessed by the DS5000FP. The entire 64k of program and 64k of
data is available. The DS5000FP maps 32k of this space into the SRAM connected to the Byte-wide bus.
This is the area from 0000h to 7FFFh (32k) and is reached via CE1 . Any area not mapped into the NV
RAM is reached via the Expanded bus on Ports 0 & 2. Selecting CE2 provides another 32k of potential
data storage. When CE2 is used, no data is available on the ports. The memory map is covered in detail in
the User’s Guide section of the Secure Microcontroller Data Book.
Figure 3 illustrates a typical memory connection for a system using 8k bytes of SRAM. Figure 4 shows a
similar system with 32 kbytes. The Byte-wide Address bus connects to the SRAM address lines. The bi-
directional Byte-wide data bus connects the data I/O lines of the SRAM. CE1 provides the chip enable
and R/ W is the write enable. An additional RAM could be connected to CE2 , with common connections
for R/ W , BA14-0, and BD7-0.
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