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software/liblitedram/sdram: Remove wraps around in sdram_leveling_center_module. 

Adding wraps around capability will have to be discussed, if implemented this has to
be done very carefully since there are no relation between the total delay that can
be compensated through the I/O-DELAYs and the SDRAM clock period.

As implemented, it also produced confusing values in the logs:

m0:0 m1:0
Read leveling:
  m0, b0: |00000000000000000000000000000000| delays: -
  m0, b1: |00000000000011111111111111100000| delays: 19+-07
  m0, b2: |00000000000000000000000000001111| delays: 14+-17
  m0, b3: |00000000000000000000000000000000| delays: -
  m0, b4: |00000000000000000000000000000000| delays: -
  m0, b5: |00000000000000000000000000000000| delays: -
  m0, b6: |00000000000000000000000000000000| delays: -
  m0, b7: |00000000000000000000000000000000| delays: -
  best: m0, b01 delays: 19+-07
  m1, b0: |00000000000000000000000000000000| delays: -
  m1, b1: |00000000000011111111111111000000| delays: 19+-07
  m1, b2: |00000000000000000000000000001111| delays: 15+-17
  m1, b3: |00000000000000000000000000000000| delays: -
  m1, b4: |00000000000000000000000000000000| delays: -
  m1, b5: |00000000000000000000000000000000| delays: -
  m1, b6: |00000000000000000000000000000000| delays: -
  m1, b7: |00000000000000000000000000000000| delays: -
  best: m1, b01 delays: 19+-07
Switching SDRAM to hardware control.

--> 14+-17 and 15+-17 are confusing.
This commit is contained in:
Florent Kermarrec 2021-04-26 17:24:53 +02:00
parent a6c5fd7aed
commit 48ec20e2ef
1 changed files with 0 additions and 6 deletions
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6
litex/soc/software/liblitedram/sdram.c
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@ -877,12 +877,6 @@ static void sdram_leveling_center_module(
delay_max = delay;
}
/* Extend the range if it wraps around */
if (delay_min_next > 0) {
delay_min = delay_min_next;
delay_max += SDRAM_PHY_DELAYS;
}
if (show_long)
printf("| ");