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Renesas SH7781 User Manual

Page 562

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12. DDR2-SDRAM Interface (DBSC2)

Rev.1.00 Jan. 10, 2008 Page 532 of 1658
REJ09B0261-0100

MCK0,
MCK1

MA[14:11 ]
MA[9:0]

MBA[2:0]

MCKE

MCS

MRAS

MCAS

MWE

MA[10]

ACT

bank A

READ
bank A

Invalid

Invalid

MDQS[3:0]

MDQ[31:0]

MDM[3:0]

Invalid

Invalid

Invalid

SDRAM
command

Valid

Invalid

READ
bank A

Invalid

Invalid

Valid

Invalid

Invalid

Invalid

Valid

Invalid

Valid

Valid

Valid

Valid

Valid

Valid

High level

Example of CL = 3

Read data

Figure 12.9 Waveforms for 32-Byte Reading

(When the Bus Width Is Set to 32 Bits)

Figure 12.10 shows waveforms for 1/2/4/8/16-byte writing when the bus width is set to 32 bits. In
this case, single-writing is performed in which the WRITE command is issued once. In this
example, write access processing is executed for bank A after the ACT command is issued, but
when there is a page hit, access begins with the issue of the WRITE command.