On Friday, February 11, 2011 11:01:40 pm Albert ARIBAUD wrote: > Le 12/02/2011 07:42, Aaron Williams a écrit : > > I've placed the results of the scan below. > > > > The problem is that in 8-bit mode the code that scans the CFI does not > > follow the specification. > > > > In the specification to read the CFI data you write 0x98 to address 0xAA, > > not address 0x55 as you do in 16-bit mode. flash_offset_cfi is set to > > 0x55 which in this case is wrong and won't work. When it tries 16-bit > > mode then it writes to address 0xAA which causes it to work. > > Let us see the specs, then. The specs I have (admittedly not necessarily > the latest: I use JESD 68.01, september 1999) state the following: > > "Nonvolatile memory devices are assumed to power up in a read-only > state. Independent of that assumption, the Query structure contents must > be able to be read at the specific address locations following a single > system write cycle where: 1) a 98h Query command code is written to 55h > address location within the device’s address space (in maximum device > buswidth), and 2) the device is in any valid read state, such as “Read > Array” or “Read ID Data”. > > I read "55h address location within the device’s address space (in > maximum device buswidth" as implying that 0x55 is the only address to > use but is in device bus terms, and that may mean different CPU > addresses for different devices types: for x8 devices, one should access > the byte address 0x55 because the device bus is in bytes, whereas for > x8/x16 and x16 devices, one should access byte address 0xAA because it > translates to x16 device bus address 0x55 -- regardless of actual x8 or > x16 mode. > > Are we in sync here?
This is wrong. The address is actually 0xAA in x8 mode and 0x55 in x16 mode according to the data sheet. > > Now it's been a long time since I last looked at my ED Mini V2 Flash, > but I should be able to dig it up and do a test within one or two hours. > > > -Aaron > > > Here's the results of the scan: > Yes, that's what U-boot *CFI code* does, but I'd like to see what very > basic writes and reads give without any detection logic involved. > > Amicalement, When I use the addresses and data shown in the datasheet, everything responds as it should using mw.b and md.b. Octeon ebb6300(ram)# mw.b 0x1f400000 0xf0 Octeon ebb6300(ram)# mw.b 0x1f400aaa 0xaa Octeon ebb6300(ram)# mw.b 0x1f400555 0x55 Octeon ebb6300(ram)# mw.b 0x1f400aaa 0x90 Octeon ebb6300(ram)# md.b 0x1f400000 1 1f400000: 01 . Octeon ebb6300(ram)# md.b 0x1f400002 1 1f400002: 7e ~ Octeon ebb6300(ram)# md.b 0x1f400004 1 1f400004: 00 . Octeon ebb6300(ram)# mw.b 0x1f400000 0xf0 Octeon ebb6300(ram)# mw.b 0x1f4000AA 0x98 Octeon ebb6300(ram)# md.b 0x1f400020 1f400020: 51 Q Octeon ebb6300(ram)# md.b 0x1f400022 1f400022: 52 R Octeon ebb6300(ram)# md.b 0x1f400024 1f400024: 59 Y Octeon ebb6300(ram)# md.b 0x1f400026 1f400026: 02 . Octeon ebb6300(ram)# md.b 0x1f400028 1f400028: 00 . -Aaron _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot