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Dram: 60ns, cpu: 25mhz, random read/write cycle, Dram: 60ns, cpu: 25mhz, page-mode read/write cycle – Epson S1C33210 User Manual

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APPENDIX A EXTERNAL DEVICE INTERFACE TIMINGS

A-98

EPSON

S1C33210 PRODUCT PART

DRAM: 60ns, CPU: 25MHz, random read/write cycle

1

RAS cycle

CAS cycle

RAS precharge

2

t

RAS

2

BCLK

A[11:0]

#RAS

#CAS

#RD

D[15:0](RD)

#WE

D[15:0](WR)

ROW #1

RD data

;;;;;;;;;

;;;;;;;;;

ROW #2

;;;;;

;;;;;

;;

;;

WR data

;;;

;;;

COL #1

DRAM: 60ns, CPU: 25MHz, page-mode read/write cycle

1

RAS cycle

CAS cycle

RAS precharge

2

CAS cycle

2

2

t

RAS

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: 60ns, CPU: 25MHz, CAS-before-RAS refresh cycle

1

1

RPC delay

Fixed

Refresh RAS pulse width

2

RAS precharge

2

t

RPC

t

CSR

t

CHR

t

RAS

BCLK

#RAS

#CAS