r8a77850anbg Renesas Electronics Corporation., r8a77850anbg Datasheet - Page 520

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

12. DDR2-SDRAM Interface (DBSC2)
Rev.1.00 Jan. 10, 2008 Page 490 of 1658
REJ09B0261-0100
Bit
14 to 8
7 to 3
Bit Name
TRFC0
⎯
TRFC6 to
Initial
Value
000 0101
All 0
R/W
R/W
R
Description
tRFC (REF-ACT/REF period) Setting Bits
These bits set the REF-ACT/REF minimum period
constraint These bits should be set according to the
DDR2-SDRAM specifications. The number of cycles is
the number of DDR clock cycles.
000 0000: Setting prohibit (If specified, correct operation
000 0100: Setting prohibit (If specified, correct operation
000 0101: 6 cycles
000 0110: 7 cycles
100 0001: 66 cycles
100 0010: Setting prohibit (If specified, correct operation
111 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.
:
:
:
cannot be guaranteed.)
cannot be guaranteed.)
cannot be guaranteed.)
cannot be guaranteed.)