NEC uPD78053(A) Manuale Utente

µ

7

0

Symbol

IXS

6

0

5

0

4

0

3

IXRAM3

2

IXRAM2

1

IXRAM1

0

IXRAM0

Address

FFF4H

0AH

After

Reset

Internal extension RAM capacity selection

IXRAM3 IXRAM2 IXRAM1

1024 bytes

1

0

1

Setting prohibited

Other than above

IXRAM0

0

R/W

W

0 bytes

1

1

0

0

The 

µ

PD78P058 allows users to define its internal expansion RAM size using the internal expansion RAM size

switching register (IXS), so that the same memory mapping as that of a mask ROM version with a different-size  internal

expansion RAM is possible.  The IXS is set by an 8-bit memory manipulation instruction.

RESET signal input sets IXS to 0AH.

The value in the IXS that has the identical memory map to the mask ROM versions is given in Table 26-5.

Pertinent mask ROM versions

Value set to IXS

µ

PD78052, 78052Y

µ

PD78053, 78053Y

µ

PD78054, 78054Y

µ

PD78055, 78055Y

µ

PD78056, 78056Y

µ

PD78058, 78058Y

If a program for the 

µ

PD78P058 or 78P058Y which

includes “MOV IXS, #0CH” is implemented with the

µ

PD78055, 78055Y, 78056, or 78056Y, this

instruction is ignored and causes no malfunction.

0CH

0AH