USER'S GUIDE

MEMORY INTERCONNECT USING THE 128K SRAM Figure 5±5

 

 

 

 

 

 

128K x 8

 

DS5001FP/DS5002FP

 

 

 

SRAM

13

VCC

VCCO

12

28

VCC

 

+5v

 

 

 

54

VLI

R/W

10

27

WE

 

+3v

 

CE1

74

20

CS1

CS2

 

 

 

 

 

 

CE2

2

2

A16

OE

 

 

 

 

 

PORT0

 

 

 

 

 

 

 

CE3

63

31

A15

 

 

 

 

 

 

 

PORT1

 

 

 

 

 

 

 

BA14±BA0

 

 

A14±A0

 

 

PORT2

 

 

 

 

 

 

 

BD7±BD0

 

 

D7±D0

 

 

PORT3

 

 

16

GND

 

 

 

 

 

 

 

52

GND

 

14

 

 

 

 

MSEL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

30

22

In the 128K x 8 configuration, the microprocessor con- verts the CE3 into A15 and CE2 into A16. Grounding the MSEL pin causes this configuration. The physical loca- tion of program memory will be between addresses 00000 to 0FFFFh. Data memory will be located between 10000h and 1FFFFh. These physical locations are transparent to the user. From a software perspective, both program and data are located between 0000 and FFFFh. When the MSEL pin is grounded, the device cannot be partitioned. The MSL bit accessed through the bootstrap loader is used to select access to the 64KB data or 64KB program segment via the loader in the 128K x 8 configuration.

The Soft Microcontroller line has two modules based on the DS5001 series. The DS2251T 128K Micro Stik uses

a DS5001FP. The DS2252T Secure Micro Stik is based on the DS5002FP. All computing features are derived from the DS5001. The DS5002 device provides memory security features in addition. The modules are available in 32K, 64K, and 128K byte versions. Two ex- ample block diagrams are shown below.

Figure 5±6 is a block diagram of the DS2251T with 128K bytes of NV RAM. This part can also be built with 32K or 64K bytes. In this case, the 128K RAM is replaced with one or two 32K byte RAMs. Figure 5±7 shows a DS2252T with 32K bytes of RAM. This part is also avail- able in 64K or 128K byte versions. For 64K, two RAMs are used. For 128K, the single 128K SRAM is used. This is entirely transparent to the user and is provided for completeness.

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Mitsubishi DS5000TK, DS907x SIP manual Memory Interconnect Using the 128K Sram ±5