Mitsubishi DS5000TK, DS907x SIP Partitionable Memory MAP for DS5001/DS5002 Series ±5, CE1 CE3 CE4

USER'S GUIDE

PARTITIONABLE MEMORY MAP FOR DS5001/DS5002 SERIES Figure 4±5

FFFFh

PARTITION

ADDR.

BYTE±WIDE

BUS ACCESS

0000

PROGRAM

MEMORY

LEGEND:

=BYTE±WIDE ACCESS (NONVOLATILE RAM)

PES=0

BYTE±WIDE

BUS ACCESS

DATA

MEMORY

64K

RANGE

ADDRESS

= EXPANDED BUS ACCESS ON PORTS 0 AND 2

The non±partitionable mode allows the maximum amount of memory to be used on the Byte±wide bus. A non±partitionable mode would be used because the 8051 architecture is restricted to a total of 64K program and 64K data (without bank switching). This means that if the maximum amount of either program or data (or both) is needed, partitioning can not be done. The DS5001/DS5002 series accommodates these situa- tions with four selections of non±partitionable (PM=1) memory control shown below. These are selected using

the Range bits when PM=1. Also note the MSEL signal. This is a pin on DS5001/DS5002 series devices that tells the processor whether multiple 32K RAMs or a 128K RAM is being used. When MSEL=0, a single 128K device is used. It is not possible to partition the device when MSEL=0, and the state of the partition bits will be ignored. The four selections are as follows. The non± partitionable memory map is shown in Figure 4±6. Byte±wide bus segments begin at 0000h.

MSEL

RG1

RG0

PROGRAM

DATA

PROGRAM ACCESS

DATA ACCESS

1

0

0

32K

64K

1

@ 32K,

2

@ 32K,

and

CE1

CE3

CE4

1

0

1

64K

32K

2

@ 32K,

and

1

@ 32K,

CE1

CE2

CE3

1

1

0

64K

64K

2

@ 32K,

and

2

@ 32K,

and

CE1

CE2

CE3

CE4

0

1

1

64K

64K

1

@ 128K X 8, for both program and data

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