York, ok - will give it a try tomorrow. Cheers, André York Sun <york...@freescale.com> hat am 6. April 2011 um 18:37 geschrieben:
> On Wed, 2011-04-06 at 10:18 +0200, Andre Schwarz wrote: > > Kim, York, > > > > >> I have made some mods to spd_sdram.c for various reason: > > >> > > >> 1. > > >> use SPD setup also for soldered RAM. > > >> This allows DDR mounting options without U-Boot change because SPD data > > >> is written during in-circuit/boundary-scan testing. > > > not sure I understand this - board with soldered RAM can't physically > > > get the SPD data from RAM, yet SPD data were somehow acquired and > > > written into some ROM, so spd_sdram() is still needed to parse& > > > program the controller without requiring a new u-boot binary? > > SPD data is nothing more than an I2C-EEPROM soldered on each memory module > > containing the physical details of the memory devices. > > Since I already have an I2C-EEPROM on the board I can use it for SPD > > data, i.e. > > the board's memory is configured using normal detection routines. > > > > During production (exactly: board testing) the EEPROM will be programmed > > with an SPD > > table matching the soldered memory devices. This gives some flexibility > > regarding size and > > speed grades ... some devices have pretty short life-cycles. > > That's right. If you have the SPD in I2C-EEPROM, you have a real SPD as > far as software concerns. Just provide the I2C address. > > > >> 3. > > >> for optimized signal integrity and power consumption we need more > > >> influence on > > >> the on-die termination. Although the assumed default values are working > > >> they > > >> are far from ideal. > > > board specific things like this are perfectly acceptable, of course. > > ok. > > > however, it should not be being done by glittering old-83xx/spd_sdram > > > with an extra #ifdef for every new parameter > > > > ok - what about this : > > > > #if !defined(CONFIG_SYS_DDR_MODE_ODT_VALUE) > > #define CONFIG_SYS_DDR_MODE_ODT_VALUE 0x40 > > #endif > > > > mode_odt_enable = CONFIG_SYS_DDR_MODE_ODT_VALUE; > > > > > > I really can't think of this change being a problem for anybody. > > > > I would suggest to put it in fsl_ddr_board_options() in ddr.c under the > board directory. There you can override any options, including > > popts->cs_local_opts[i].odt_rd_cfg > popts->cs_local_opts[i].odt_wr_cfg > popts->cpo_override > > > > York > > >-- Gruß, André Schwarz MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler Registergericht: Amtsgericht Stuttgart, HRB 271090 Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner
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