Renesas SH7781 - Manual (Page 573)

12. DDR2-SDRAM Interface (DBSC2)
Rev.1.00 Jan. 10, 2008 Page 543 of 1658
REJ09B0261-0100
MCK0,
MCK1
MA[14:11]
MA[9:0]
MBA[2:0]
MCKE
MCS
MRAS
MCAS
MWE
MA[10]
ACT
any
bank
tRFC
Invalid
Invalid
Invalid
Invalid
MDQS[3:0]
MDQ[31:0]
MDM[3:0] Invalid
Invalid
Invalid
Invalid
REF SDRAM
command
READ
any
bank
Invalid
Invalid
Invalid
= 6 cycles
Valid
Valid
Valid
Valid
Valid
Valid
High level
Figure 12.20 tRFC
Figure 12.20 is an example of a case in which, after issuing a REF command, a READ request is
issued. In order to issue the ACT commend after issuing the REF command, the DBSC2 waits for
a time stipulated by tRFC.