r8a77850anbg Renesas Electronics Corporation., r8a77850anbg Datasheet - Page 569

• Manufacturer Part Number: r8a77850anbg
• Description: Renesas 32-bit Risc Microcomputer Superh? Risc Engine Family
• Manufacturer: Renesas Electronics Corporation.

Figure 12.16 shows a case in which, after a write request, access occurs requiring that bank B be
closed. After the issue of a WRITE command, it is necessary to wait for time tWR or longer after
output of the write data before issuing a PRE command.
Example of CL = 3
MCK0,
MCK1
MCKE
MCS
MRAS
MCAS
MWE
MA[14:11]
MA[9:0]
MA[10]
MBA[2:0]
MDQS[3:0]
MDM[3:0]
MDQ[31:0]
SDRAM
command
WRITE
bank A
Valid
Valid
Valid
Invalid
Invalid
Write data
High level
Invalid
Invalid
Figure 12.16 tWR
Invalid
tWR
= 3 cycles
bank A
PRE
Valid
Rev.1.00 Jan. 10, 2008 Page 539 of 1658
Invalid
Invalid
12. DDR2-SDRAM Interface (DBSC2)
Invalid
Invalid
bank A
ACT
Valid
Valid
Valid
Invalid
Invalid
Invalid
REJ09B0261-0100
WRITE
bank A
Valid
Valid
Valid