[coreboot] SST25VF016B (2MB) flash on m57sli (IT8716F).
c-d.hailfinger.devel.2006 at gmx.net
Thu Jan 17 03:26:11 CET 2008
On 17.01.2008 02:48, Ward Vandewege wrote:
> Hi Ronald,
> On Thu, Jan 17, 2008 at 12:13:48AM +0100, Ronald Hoogenboom wrote:
>> Problem1 (for reading) is solved by NOT using the mmap method for
>> reading the flash contents, but using outb() for sending the flash read
>> commands (using a specific 25vf016 read function). Also the normal read
>> command is only supported up to 25MHz by this chip, so I cannot use the
>> 33MHz speed as used normally by spi.c. There is also a 'high speed' read
>> command (0x0b), which inserts an extra dummy byte between address and
>> data, but as the 8716 only allows max. 3 bytes read per io transfer, the
>> gain (3 bytes per io transfer @ 16MHz versus 2 bytes per io transfer @
>> 33MHz) is negligible.
> Can you elaborate a bit about that - I see the two read speeds in the
> datasheet, but how do you get to 16MHz in that last sentence?
33 MHz /2 (at least that's how the IT8716F datasheet calls it.
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