[U-Boot] Question on EON EN29LV160B Flash Memory

[Niklaus Giger]

Hi Agostino


-------- Original-Nachricht --------
> Datum: Wed, 14 Oct 2009 13:11:17 +0200
> Von: Stefan Roese <sr at denx.de>
> An: u-boot at lists.denx.de
> CC: Niklaus Giger <niklaus.giger at netstal.com>, SETTE AGOSTINO - technolabs <Agostino.Sette at technolabs.it>
> Betreff: Re: [U-Boot] Question on EON EN29LV160B Flash Memory

> On Wednesday 14 October 2009 11:20:21 SETTE AGOSTINO - technolabs wrote:
> > I am going to prepare a new U-Boot with a HW which has on board an EON
> >  EN29LV160B Flash Memory. As far as I see in the latest U-Boot tree this
> >  kind of FLASH is not yet managed but anyhow I found some infos on EON
> >  manufacturer into the file u-boot/include/flash.h and more exactly
> > 
> >  173 /* Manufacturers inside bank 1 have ids like 0x01xx01xx */
> >  174 #define EON_MANUFACT    0x011C011C      /* EON     manuf. ID in
> >  D23..D16, D7..D0 */
> > 
> > I have an EON EN29LV160B Flash Memory datasheet and on the Manufacturer
> ID
> >  I have different infos which indicate differente values, as here
> reported
> > 
> >  173 /* Manufacturers inside bank 1 have ids like 0x7Fxx7Fxx */
> >  174 #define EON_MANUFACT    0x7F1C7F1C      /* EON     manuf. ID in
> >  D23..D16, D7..D0 */
> > 
> > Is this correct?
> 
> Yes, this looks correct on first glance. But I'm not really sure. I added 
> Niklaus Giger to Cc, who introduced this define.
> 
> Niklaus, could you please comment here? Thanks.
> 

See www.jedec.org/download/search/jep106Z.pdf.

I would like to cite the "JEDEC Standard  Manufacturer ID Codes.pdf" 
chapter "2 Scope":

> 
> The manufacturer’s identification code is defined by one or more eight (8) 
> bit fields, each
> consisting of seven (7) data bits plus one (1) odd parity bit. The 
> manufacturer’s identification
> code as shown in Table 1, is assigned, maintained and updated by the JEDEC 
> office. It is a
> single field, limiting the possible number of vendors to 128. To expand the 
> maximum number of
> identification codes, a continuation scheme has been defined. The code 7F, 
> as shown in Table 1,
> indicates that the manufacturer’s code is beyond the limit of this field and 
> the next sequential
> manufacturer’s identification field is used. Multiple continuation fields are 
> permitted and when
> used, shall comprise of the identification code. 
At the momemnt we defined 6 additional table, but potentially there could be even more. Where there is place for 16 bit values.
- ID's of the the table 1 (0xXX) get IDs of 0x00xx.
- ID's of the the table 2 (0xXX) get IDs of 0x01xx.
- ID's of the the table 3 (0xXX) get IDs of 0x02xx.
- ID's of the the table 4 (0xXX) get IDs of 0x03xx.
Using the data in the above mentioned PDF and following this
rule the manufacturer "Jennic" would receive ID 0x0686.

The proposed value of #define EON_MANUFACT 0x7F1C7F1C
does not fit into 16 bits.

And don't forget to follow Stefan's remark about using JEDEC-
lecagy. Then you should not have any problems.

Best regards

Niklaus

> > Furthermore, if I would like to add this kind of flash I have to modify,
> >  add the flash type/config, the file
> > 
> > u-boot/drivers/mtd/jedec_flash.c
> > 
> > or
> > 
> > u-boot/drivers/mtd/cfi_flash.c
> 
> Changes in jedec_flash.c should be sufficient. Even though you need to
> enable 
> the CFI driver (CONFIG_FLASH_CFI_DRIVER) and this JEDEC legacy driver 
> (CONFIG_FLASH_CFI_LEGACY).
>  
> Cheers,
> Stefan
> 
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-- 
Niklaus Giger
Switzerland

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