8XC196MC, MD, MH USER’S MANUAL

Figure 15-13 shows a system that uses the dynamic bus-width feature. (The CCR bits, BW0 and BW1, are set.) Code is executed from the two EPROMs and data is stored in the byte-wide RAM. The RAM is in high memory. It is selected by driving AD15 high, which also selects the 8-bit bus-width mode by driving the BUSWIDTH signal low.

BUSWIDTH

 

CS#

CS#

 

CS#

 

 

 

 

 

 

 

A15

 

 

 

 

AD15:8

74AC

A14:8

A14:8

A12:8

A12:8

 

373

A13:7

A13:7

 

 

 

 

 

 

 

 

 

LE

 

 

 

 

 

 

 

D15:8

 

 

 

 

ALE

 

 

D7:0

 

D7:0

 

 

 

 

 

 

 

 

16K×8

16K×8

 

8K×8

8XC196

 

EPROM

EPROM

 

RAM

 

LE

(High)

(Low)

 

 

 

AD7:0

74AC

A7:1

A7:1

A7:0

A7:0

 

373

A6:0

A6:0

 

 

 

 

 

 

 

 

 

 

OE#

OE#

 

OE#

WE#

RD#

 

 

 

 

 

 

WR#

 

 

 

 

 

 

 

 

 

 

 

 

A3087-01

Figure 15-13. 16-bit System with Dynamic Bus Width

15-24

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Intel 8XC196MD, 8XC196MH, 8XC196MC manual Buswidth CS#, Eprom RAM, Oe# We# Rd# Wr#