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SH7785 Datasheet, PDF (487/1692 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer | |||
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12. DDR2-SDRAM Interface (DBSC2)
Section 12 DDR2-SDRAM Interface (DBSC2)
The DDR2-SDRAM interface (DBSC2) controls the DDR2-SDRAM.
12.1 Features
⢠Supports 32-bit and 16-bit external data bus widths
⢠Supports from DDR2-600 (controller operation at 300 MHz) to DDR2-400 (controller
operation at 200 MHz)
⢠Connects to 64-bit SuperHyway internal bus
⢠Supports 1:1 clock ratio between SuperHyway clock and DDR clock
⢠Queue provided for interface with SuperHyway
⢠During power-on reset, pin MODE8 can be used to switch between big- and little-endian
⢠Supports 4-bank and 8-bank DDR2-SDRAMs
⢠Supports sequential mode with burst length 4
⢠Supports Additive Latency (AL) of 0 only
⢠Supports differential data strobe signal (DQS, DQS)
Note: RDQS is not supported.
⢠Supports self-refresh
⢠Supports power supply backup mode
⢠Supported DDR2-SDRAM addresses à bit widths (total capacity) are as follows.
For details, refer to tables 12.12 through 12.19.
(When using 8-bank products, please refer to section 12.5.8, Important Information Regarding
Use of 8-Bank DDR2-SDRAM Products.)
⯠DDR2-SDRAM data bus width: 32 bits
⢠Two 256 Mbits (16M à 16 bits) connected in parallel (total capacity = 512 Mbits)
⢠Four 256 Mbits (32M à 8 bits) connected in parallel (total capacity = 1 Gbit)
⢠Two 512 Mbits (32M à 16 bits) connected in parallel (total capacity = 1 Gbit)
⢠Four 512 Mbits (64M à 8 bits) connected in parallel (total capacity = 2 Gbits)
⢠Two 1 Gbit (64M à 16 bits) connected in parallel (total capacity = 2 Gbits)
⢠Four 1 Gbit (128M à 8 bits) connected in parallel (total capacity = 4 Gbits)
⢠Two 2 Gbits (128M à 16 bits) connected in parallel (total capacity = 4 Gbits)
⢠Four 2 Gbits (256M à 8 bits) connected in parallel (total capacity = 8 Gbits)
Rev.1.00 Jan. 10, 2008 Page 457 of 1658
REJ09B0261-0100
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