Section 12 DDR-SDRAM Interface (DDRIF)
Rev. 1.00 Oct. 01, 2007 Page 430 of 1956
REJ09B0256-0100
12.5 Operation
12.5.1 DDR-SDRAM
Access
The DDR-SDRAM is accessed with a burst length of 2. Read or write commands that hit the page
are issued continuously and read data continuously.
ACT
WR
Write command
Write data
WR
WR
WR
D
D
D
D
D
D
D
D
ACT
RD
read command
read data
RD
RD
RD
D
D
D
D
D
D
D
D
Figure 12.4 DDR-SDRAM Access
12.5.2 DDR-SDRAM
Initialization Sequence
Since the internal state of the DDR-SDRAM is undefined immediately after a power-on, initialize
the SDRAM according to the following sequence. Otherwise the device may be damaged.
An example of the initialization sequence for the DDR-SDRAM is shown below. For details, see
each memory manufacturer's datasheet.
1. Turn on the four power supplies to the DDR-SDRAM in the following order: VDD, VDDQ,
VREF, and VTT.
2. After the power supply, reference voltage, and clock are stabilized, maintain the current state
for at least 200
µ
s.
3. Perform a dummy read to any DDR-SDRAM address.
4. Set MIM to enable the DDR-SDRAM controller, set the endian mode, and so on.
5. Set SDR and STR.
6. Use the SMS field in SCR to enable the CKE pin.
7. Use the SMS field in SCR to issue the all-bank precharge (PREALL) command.
8. Use SDMR to issue the EMRS command and enable the DLL.
Содержание SH7763
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Страница 144: ...Section 3 Instruction Set Rev 1 00 Oct 01 2007 Page 78 of 1956 REJ09B0256 0100 ...
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Страница 378: ...Section 9 Interrupt Controller INTC Rev 1 00 Oct 01 2007 Page 312 of 1956 REJ09B0256 0100 ...
Страница 514: ...Section 12 DDR SDRAM Interface DDRIF Rev 1 00 Oct 01 2007 Page 448 of 1956 REJ09B0256 0100 ...
Страница 630: ...Section 13 PCI Controller PCIC Rev 1 00 Oct 01 2007 Page 564 of 1956 REJ09B0256 0100 ...
Страница 686: ...Section 14 Direct Memory Access Controller DMAC Rev 1 00 Oct 01 2007 Page 620 of 1956 REJ09B0256 0100 ...
Страница 710: ...Section 16 Clock Pulse Generator CPG Rev 1 00 Oct 01 2007 Page 644 of 1956 REJ09B0256 0100 ...
Страница 732: ...Section 17 Watchdog Timer and Reset WDT Rev 1 00 Oct 01 2007 Page 666 of 1956 REJ09B0256 0100 ...
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Страница 772: ...Section 19 Timer Unit TMU Rev 1 00 Oct 01 2007 Page 706 of 1956 REJ09B0256 0100 ...
Страница 824: ...Section 21 Compare Match Timer CMT Rev 1 00 Oct 01 2007 Page 758 of 1956 REJ09B0256 0100 ...
Страница 1060: ...Section 23 Gigabit Ethernet Controller GETHER Rev 1 00 Oct 01 2007 Page 994 of 1956 REJ09B0256 0100 ...
Страница 1062: ...Section 24 IP Security Accelerator SECURITY Rev 1 00 Oct 01 2007 Page 996 of 1956 REJ09B0256 0100 ...
Страница 1124: ...Section 26 I 2 C Bus Interface IIC Rev 1 00 Oct 01 2007 Page 1058 of 1956 REJ09B0256 0100 ...
Страница 1184: ...Section 27 Serial Communication Interface with FIFO SCIF Rev 1 00 Oct 01 2007 Page 1118 of 1956 REJ09B0256 0100 ...
Страница 1350: ...Section 30 SIM Card Module SIM Rev 1 00 Oct 01 2007 Page 1284 of 1956 REJ09B0256 0100 ...
Страница 1484: ...Section 33 Audio Codec Interface HAC Rev 1 00 Oct 01 2007 Page 1418 of 1956 REJ09B0256 0100 ...
Страница 1560: ...Section 35 USB Host Controller USBH Rev 1 00 Oct 01 2007 Page 1494 of 1956 REJ09B0256 0100 ...
Страница 1720: ...Section 37 LCD Controller LCDC Rev 1 00 Oct 01 2007 Page 1654 of 1956 REJ09B0256 0100 ...
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