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
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