Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Overriding default Gatex[].PhaseServoDir
#1
My system has an ACC 5E and two ACC-24E3A boards. I would like to set this up like this:
Gate2[0].PhaseServoDir=3 // Not using this as a macro card, just I/O, may remove at some future point
Gate3[0].PhaseServoDir=0 // Clock source for servos
Gate3[1].PhaseServoDir=3 // external clock form first 24E3A

The problem is that on reset (power up or $$$) it always reverts to:
Gate2[0].PhaseServoDir=0
Gate3[0].PhaseServoDir=3
Gate3[1].PhaseServoDir=3

Is there a way to make the PPmac do this?
Reply
#2
Jeff,

We follow the following rules for setting/selecting the clock source in Power PMAC.

1. Lowest Addressed Gate3 with MACRO option.
2. Lowest Addressed Gate2 with MACRO option.
3. Lowest Addressed Gate3 with Servo or IO option
4. Lowest Addressed Gate2 with IO option
3. Lowest Addressed Gate1.

regardless of the source for the clock, there can only be one phase and one servo clock present throughout the Power PMAC unit. So it doesn't make a difference which gate is the source for the clock as long as all the clock settings match and the internal phase lock loop will ensure the synchronization of gates.

Although it is possible to reassign the clock source, there is no reason to do so.

Would you explain the reason you need to do this?
Sina Sattari
Chief Engineer
Delta Tau Data Systems, Inc.
Reply
#3
(04-17-2012, 09:20 AM)Sina Wrote: Would you explain the reason you need to do this?

Because as I said, the ACC-5E may or may not be in the system and If I could establish the clock as coming from the ACC-24E3A, which will ALWAYS be in the system, I will not have to alter my configuration depending on if the optional 5E is installed. In addition the Phase frequency divisor for the ACC-24E3 is a floating point number based on a 300 MHz internal clock and affords more flexibility in selecting phase and servo frequencies than an integer divisor of 117,964.8 KHz.
Reply
#4
(04-17-2012, 01:16 PM)JeffLowe Wrote:
(04-17-2012, 09:20 AM)Sina Wrote: Would you explain the reason you need to do this?

Because as I said, the ACC-5E may or may not be in the system and If I could establish the clock as coming from the ACC-24E3A, which will ALWAYS be in the system, I will not have to alter my configuration depending on if the optional 5E is installed. In addition the Phase frequency divisor for the ACC-24E3 is a floating point number based on a 300 MHz internal clock and affords more flexibility in selecting phase and servo frequencies than an integer divisor of 117,964.8 KHz.
Any suggestions on how to accommodate this without having to use two different base configurations?

Reply
#5
There is a way to do this, however you have to keep in mind that Delta Tau strongly recommend users not to change their clock source and allow the firmware to select the clock source.

In order to change the clock source, you have to make sure to change multiple variables at the same time. Failure to change these clocks, will result in loss of clock and a watchdog on the CPU.

Please make sure to enter the following all as ONE LINE COMMAND to pmac.

Code:
Gate3[0].PhaseServoDir=0 Gate3[1].PhaseServoDir=3 Cid[4].Dir=0 Gate2[0].PhaseServoDir=3

The Cid[x] structure is for Delta Tau internal use only. If you need a reference to how x relates to your DSPGates, please check the Power PMAC Software Reference manual, section titled "UMAC Addressing Summary for Turbo and Power PMAC".
Sina Sattari
Chief Engineer
Delta Tau Data Systems, Inc.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)