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Dram: 70ns, cpu: 33mhz, random read/write cycle, Dram: 70ns, cpu: 33mhz, page-mode read/write cycle – Epson S1C33210 User Manual

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APPENDIX A EXTERNAL DEVICE INTERFACE TIMINGS

A-94

EPSON

S1C33210 PRODUCT PART

DRAM: 70ns, CPU: 33MHz, random read/write cycle

2

RAS cycle

CAS cycle

RAS precharge

3

t

RC

t

RAD

t

RAH

t

RCD

t

RAC

t

OAC

t

AA

t

CAC

t

OFF

t

CAS

t

ASC

t

RAS

t

ASR

t

WP

t

RP

2

BCLK

A[11:0]

#RAS

#CAS

#RD

D[15:0](RD)

#WE

D[15:0](WR)

ROW #1

RD data

;;;;;;;;;

;;;;;;;;;

ROW #2

;;;;;;;;;

;;;;;;;;;

;;;;

;;;;

t

DH

t

DS

WR data

;;;

;;;

COL #1

DRAM: 70ns, CPU: 33MHz, page-mode read/write cycle

2

RAS cycle

CAS cycle

RAS precharge

3

CAS cycle

3

t

PC

t

ACP

t

CP

t

RAS

2

BCLK

A[11:0]

#RAS

#CAS

#RD

D[15:0](RD)

#WE

D[15:0](WR)

ROW #1

RD data

;;;;;;

;;;;;;

;;;;;;;;;

;;;;;;;;;

RD data

;;;;;;;;;

;;;;;;;;;

WR data

;;;

;;;

WR data

COL #1

COL #2

DRAM: 70ns, CPU: 33MHz, CAS-before-RAS refresh cycle

1

1

RPC delay

Fixed

Refresh RAS pulse width

3

RAS precharge

2

t

RPC

t

CSR

t

CHR

t

RAS

BCLK

#RAS

#CAS