NEC uPD78P078 User Manual

Page 542

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542

CHAPTER 23 EXTERNAL DEVICE EXPANSION FUNCTION

Figure 23-11. External Memory Write Timing in Separate Bus Mode

(a) No wait (PW1, PW0 = 0, 0) setting

(b) Wait (PW1, PW0 = 0, 1) setting

(c) External wait (PW1, PW0 = 1, 1) setting

Note

In the separate bus mode, use of the address strobe signal is not required though it is output from

the ASTB/P67 pin.

ASTB

Note

WR

AD0 to AD7

A0 to A7

A8 to A15

Lower Address

Write Data

Higher Address

Lower Address

Hi-Z

ASTB

Note

WR

AD0 to AD7

A0 to A7

A8 to A15

Lower Address

Write Data

Higher Address

Lower Address

Internal Wait Signal

(1-clock wait)

Hi-Z

ASTB

Note

WR

Higher Address

Lower Address

AD0 to AD7

A0 to A7

A8 to A15

WAIT

Hi-Z

Lower Address

Write Data

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