[U-Boot] [PATCH] Add Boundary Devices Nitrogen6X boards

[Eric Nelson]

Hi Benoît,

On 02/19/2013 03:31 PM, Benoît Thébaudeau wrote:
> On Tuesday, February 19, 2013 10:53:48 PM, Eric Nelson wrote:
>> On 02/19/2013 01:52 PM, Benoît Thébaudeau wrote:
>>> Hi Eric,
>>>
>>> On Tuesday, February 19, 2013 9:20:48 PM, Eric Nelson wrote:
>>> [--snip--]
>>>> diff --git a/board/boundary/nitrogen6x/1066mhz_4x128mx16.cfg
>>>> b/board/boundary/nitrogen6x/1066mhz_4x128mx16.cfg
>>>> new file mode 100644
>>>> index 0000000..45b8879
>>>> --- /dev/null
>>>> +++ b/board/boundary/nitrogen6x/1066mhz_4x128mx16.cfg
>>> [--snip--]
>>>> +DATA 4, MX6_MMDC_P0_MDPDC, 0x00020036
>>>> +DATA 4, MX6_MMDC_P0_MDCFG0, 0x555B7974
>>>                                       ^A?
>>>> +DATA 4, MX6_MMDC_P0_MDCFG1, 0xDB538F64
>>>> +DATA 4, MX6_MMDC_P0_MDCFG2, 0x01FF00DB
>>>> +DATA 4, MX6_MMDC_P0_MDRWD, 0x000026D2
>>>> +DATA 4, MX6_MMDC_P0_MDOR, 0x005B1023
>>>                                     ^A?
>>>> +DATA 4, MX6_MMDC_P0_MDOTC, 0x09444040
>>>> +DATA 4, MX6_MMDC_P0_MDPDC, 0x00025576
>>>> +DATA 4, MX6_MMDC_P0_MDASP, 0x00000027
>>>> +DATA 4, MX6_MMDC_P0_MDCTL, 0x831A0000
>>>> +DATA 4, MX6_MMDC_P0_MDSCR, 0x04088032
>>>> +DATA 4, MX6_MMDC_P0_MDSCR, 0x00008033
>>>> +DATA 4, MX6_MMDC_P0_MDSCR, 0x00428031
>>>> +DATA 4, MX6_MMDC_P0_MDSCR, 0x19308030
>>>> +DATA 4, MX6_MMDC_P0_MDSCR, 0x04008040
>>>> +DATA 4, MX6_MMDC_P0_MPZQHWCTRL, 0xA1390003
>>>> +DATA 4, MX6_MMDC_P1_MPZQHWCTRL, 0xA1390003
>>>> +DATA 4, MX6_MMDC_P0_MDREF, 0x00005800
>>>> +DATA 4, MX6_MMDC_P0_MPODTCTRL, 0x00022227
>>>> +DATA 4, MX6_MMDC_P1_MPODTCTRL, 0x00022227
>>>> +DATA 4, MX6_MMDC_P0_MPDGCTRL0, 0x42720306
>>>> +DATA 4, MX6_MMDC_P0_MPDGCTRL1, 0x026F0266
>>>> +DATA 4, MX6_MMDC_P1_MPDGCTRL0, 0x4273030A
>>>> +DATA 4, MX6_MMDC_P1_MPDGCTRL1, 0x02740240
>>>> +DATA 4, MX6_MMDC_P0_MPRDDLCTL, 0x45393B3E
>>>> +DATA 4, MX6_MMDC_P1_MPRDDLCTL, 0x403A3747
>>>> +DATA 4, MX6_MMDC_P0_MPWRDLCTL, 0x40434541
>>>> +DATA 4, MX6_MMDC_P1_MPWRDLCTL, 0x473E4A3B
>>>> +DATA 4, MX6_MMDC_P0_MPWLDECTRL0, 0x0011000E
>>>> +DATA 4, MX6_MMDC_P0_MPWLDECTRL1, 0x000E001B
>>>> +DATA 4, MX6_MMDC_P1_MPWLDECTRL0, 0x00190015
>>>> +DATA 4, MX6_MMDC_P1_MPWLDECTRL1, 0x00070018
>>>> +DATA 4, MX6_MMDC_P0_MPMUR0, 0x00000800
>>>> +DATA 4, MX6_MMDC_P1_MPMUR0, 0x00000800
>>>> +DATA 4, MX6_MMDC_P0_MDSCR, 0x00000000
>>>> +DATA 4, MX6_MMDC_P0_MAPSR, 0x00011006
>>> [--snip--]
>>>
>>> tXS = tXPR = 170 ns -> 91 nCK -> 91 - 1 -> 0x5A.
>>>
>>
>> Thanks Benoît,
>>
>> I was going to bring this up in a separate thread.
>>
>> While working through the details of our 800MHz
>> variants (Solo, Dual-Lite), and x256mx16 variants,
>> I re-worked these numbers and it seems that we
>> have an off-by-one issue with those fields.
>
> Probably because it has been missed that the bit-field
 > value is the number of clock cycles minus 1.
>
Right. All of these fields are plus 1.

	MDCFG0.tRFC
	MDCFG0.tXS
	MDOR.tXPR

Since they're all in the same units, the requirements
are:
	MDCFG0.tXS >= MDCFG0.tRFC + 10nS
and
	MDOR.tXPR >= MDCFG0.tRFC + 10nS

Since we operate at ~528MHz, each clock is less than
2 nS, and we need 6 more clocks for each.

>> According to the JEDEC spec and data sheets,
>> both tXS and tXPR should be 10nS greater than tRFC.
>
> Indeed, or more precisely, max(5 nCK, tRFC + 10 ns).
>

Yep. I shortened because nothing approaches 5nCK.

And note that this is the minimum spec, not the
target.

>> Since the nominal clock for i.MX6 is 528MHz (1.89nS),
>
> I used 532 MHz because this is a more standard value, and I found several close
> different values in the documentation, so in the doubt, I chose the worst case.
> With 528 MHz, the bit-field value would be 0x59.
>

Either way, we need 6 clocks to get > 10nS.

>> this should be a delta of 6 clocks, not 5.
>
> Delta with what?
>

Sorry. I meant the Delta between MDCFG0.tRFC and the
other two fields.

>> This change should apply to mx6q_4x_mt41j128.cfg as well.
>
> Sure.
>
>> There are some other things in that file that should
>> be fixed as well. The biggest among them is the settings
>> for P1_MPWLDECTRL0/1.
>
> Note that in this series, I have only reviewed the register values that
 > changed in my series, and only for 1066mhz_4x128mx16.cfg.
>

Thanks for that. More eyeballs are better, especially when
looking at bit-fields...

Also note that these relationships make a pretty good case
for having expression support in these files.

It would be nice to express tXS and tXPR as tRFC+6.

But this is a topic for another day.

>> These settings are indicative of a fly-by topology,
>> which isn't used on SABRE Lite, and I don't think
>> is used on SABRE SD.
>>
>> 	DATA 4 0x021b480c 0x00440044
>> 	DATA 4 0x021b4810 0x00440044
>>
>> This was the primary thing that caused crashes
>> under stress on SABRE Lite and led to our flurry of
>> calibration tests as discussed here:
>>
>> 	http://boundarydevices.com/i-mx-6dq-u-boot-updates/
>
> OK. I had not looked in detail into this.
>
>> Should we take this up in a separate thread? It seems
>> un-related to our Nitrogen6X board.
>
> As you prefer. This is related to this series, but a very
 > specific subject per se.
>

I'll start a separate thread regarding the SABRE-Lite
and SABRE SD memory settings.

Regards,


Eric