r8a77850anbg Renesas Electronics Corporation., r8a77850anbg Datasheet - Page 527

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

Bit
11 to 8
7 to 4
Bit Name
RDWR3 to
RDWR0
⎯
Initial
Value
0011
All 0
R/W
R/W
R
Description
These bits set the READ-WRITE command minimum
interval constraint. These bits should be set according
to the SDRAM specifications. The number of cycles is
the number of DDR clock cycles.
0000: Setting prohibit (If specified, correct operation
0010: Setting prohibit (If specified, correct operation
0011: 4 cycles
0100: 5 cycles
1000: 9 cycles
1001: Setting prohibit (If specified, correct operation
1111: Setting prohibit (If specified, correct operation
Reserved
These bits are always read as 0. The write value should
always be 0.
Operation when a value other than 0 is written is not
guaranteed.
READ-WRITE Command Minimum Interval Setting Bits
:
:
:
cannot be guaranteed.)
cannot be guaranteed.)
cannot be guaranteed.)
cannot be guaranteed.)
Rev.1.00 Jan. 10, 2008 Page 497 of 1658
12. DDR2-SDRAM Interface (DBSC2)
REJ09B0261-0100