APPENDIX A <REFERENCE> EXTERNAL DEVICE INTERFACE TIMINGS

A.5 SRAM (70ns)

SRAM interface setup examples – 70ns

Operating

Read cycle

Write cycle

Output disable

 

 

 

 

 

 

 

 

 

frequency

Wait cycle

Read cycle

 

delay time

20MHz

2

3

3

1.5

25MHz

2

3

3

1.5

33MHz

3

4

4

1.5

SRAM interface timing – 70ns

SRAM interface

 

 

 

33MHz

25MHz

20MHz

Parameter

Symbol

Min.

Max.

Cycle

Time

Cycle

Time

Cycle

Time

<Read cycle>

 

 

 

 

 

 

 

 

 

Read cycle time

tRC

70

4

120

3

120

3

150

Address access time

tACC

70

4

120

3

120

3

150

#CE access time

tACS

70

4

120

3

120

3

150

#OE access time

tOE

40

3.5

105

2.5

100

2.5

125

Output disable delay time

tOHZ

0

30

1.5

45

1.5

60

1.5

75

<Write cycle>

 

 

 

 

 

 

 

 

 

Write cycle time

tWC

70

4

120

3

120

3

150

Address enable time

tAW

60

3.5

105

2.5

100

2.5

125

Write pulse width

tWP

55

3

90

2

80

2

100

Input data setup time

tDW

30

3

90

2

80

2

100

Input data hold time

tDH

0

0.5

15

0.5

20

0.5

25

SRAM: 70ns, CPU: 33MHz, read cycle

BCLK

tRC

A[23:0]

tACC

#CEx

tACS

#RD

tOE

 

 

 

tOHZ

 

 

RD data

D[15:0]

SRAM: 70ns, CPU: 33MHz, write cycle

BCLK

tWC

A[23:0]

tAW

#CEx

tWP

#WP

tDW tDH

D[15:0]

WR data

A-104

EPSON

S1C33210 PRODUCT PART