Ticket #12064 (closed defect: fixed)

Opened 2 years ago

Last modified 20 months ago

OFW doesn't support operation at 1 and 1.2 GHZ on XO-4

Reported by: wad Owned by: Quozl
Priority: low Milestone: 4-hardware
Component: ofw - open firmware Version: 4-A2
Keywords: xo-4 Cc: wad
Action Needed: no action Verified: no
Deployments affected: Blocked By:
Blocking:

Description

Quanta keeps requesting support for running the main cores at 1 GHz on XO-4. Currently they run at 800 MHz on XO-4 A2 motherboards.

I'm told that this requires firing up the second PLL, as the processors will no longer be synchronous to the memory interface.

As with XO-1.75, we have a GPIO (#3, w. jumpers on the motherboard) which should select the processor frequency (0 for 1 GHz, 1 for 1.2 GHz).

Quanta will have A2 boards with 1.2 GHz processors for testing by the end of next week (8/30/2012).

Change History

Changed 2 years ago by Quozl

  • owner changed from quozl to Quozl
  • status changed from new to assigned

Progress report:

  • a PLL2 control register has moved from MMP2 (0x414) to MMP3 (0x418), so the banner display in Q7A08, which is coded for MMP2, is ignorant of the core frequency and should be ignored,
  • we need fuses documentation to determine what the silicon supports, ticket 472527 relates, existing .fuses commandin Q7A08 is not valid and should be ignored,
  • a recipe for switching to 1.063 GHz has been prepared from the documentation, but it doesn't yet work, further experimentation is required,
  • in Q7A08, using .speed shows that pj4-910mhz and pj4-988mhz slows the core considerably over the default pj4-800mhz, so these also should be ignored,

Changed 2 years ago by wmb@…

Operation at 1.063 GHz is now working. There may be voltage setting changes necessary before it is stable - we have a report that 1.063 GHz is unstable if the L2 cache is on.

Changed 23 months ago by wad

Boards with 1.2GHz processors on them are now awaiting testing at QCI

Changed 23 months ago by wad

  • priority changed from high to low

Changed 22 months ago by Quozl

XO-4 with 1.2 GHz processor shows as 14xx MHz in Open Firmware banner. The calculation has lagged the CForth change. Not quite sure how pj4-speed needs to change.

Changed 20 months ago by Quozl

  • status changed from assigned to closed
  • next_action changed from code to no action
  • resolution set to fixed

Was fixed.

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