X88C75PI datasheet(14/27 Pages) XICOR

14 / 27 page

X88C75 SLIC® E2

Example 2

Applications requiring more than 8K bytes of program

memory space can be implemented using the basic

system architecture depicted in example 1 along with an

additional memory device such as the X28C256. Since

this device requires non-multiplexed address/data buses,

the X88C75 LAM feature is used to output the low order

address byte. The SFRM can be mapped to any 64x1K

page, but the X28C256 should be mapped to the upper

program memory address space and out of the E2M

address range (0000-1FFFH.) This technique may also

be used for other external byte wide memories such as

SRAMs or EPROMs.

APPLICATION EXAMPLES

This section gives examples of most widely used em-

bedded systems architectures using the X88C75 and

80C51 microcontroller. However, keep in mind that

other microcontrollers are also supported by the X88C75

and/or other SLIC devices that Xicor manufactures.

Example 1

In this system, the X88C75 is the only parallel device

residing on the multiplexed address and data bus. There

may be other peripherals on the system board which are

controlled by the ports on the X88C75. This configura-

tion maps the EEM to a program/data memory address

in the range of 0000-1FFFH. The SFRM can be mapped

to any of the 64 x 1K pages within the data memory

space.

Figure 14. Example 1

ALE

PSEN

ALE

PSEN

I/O7-I/O0

A14-A8

A15

2887 ILL F19

A7-A0

STRA

A7:0

X88C75

8051

X28C256

A15:8

AD7:0

D7:0

A15:8

STRB

RESET

Figure 15. Example 2

ALE

PSEN

ALE

PSEN

STRA

X88C75

8051

A15:8

AD7:0

STRB

2887 ILL F18

RESET

X88C75PI Datasheet(PDF) 14 Page - Xicor Inc.

X88C75PI Datasheet(HTML) 14 Page - Xicor Inc.

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Datasheet Download

Link URL