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encoder loss bits
#1
Hi,

On acc24e2a with PowerPMAC at what addresses do we find the encoder loss bits?
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#2
(07-07-2010, 02:02 PM)bradp Wrote: Hi,

On acc24e2a with PowerPMAC at what addresses do we find the encoder loss bits?

Brad,

I think it would be bits 28 and 29 of the Gate3[].Chan[].Status word based upon the memory map included at the end of ACC-24E3 manual.

Bit 28 is LossStatus which I believe changes and bit 29 latches if an encoder loss is detected. Also bit 30 gives the Count Error.
Sina Sattari
Chief Engineer
Delta Tau Data Systems, Inc.
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#3
You think it is the same for Acc24e2a as it is for acc24e3 ?
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#4
On the ACC-24E2A, the encoder loss bits are found in the Lattice chip, not the ASIC, as in the ACC-24E3.

Here are the base address offsets of the Lattice chips for each ACC-24E2x, given by the Gate1 index "i":

4: $D06040
6: $D06140
8: $D0E040
10: $D0E140
12: $D16040
14: $D16140
16: $D1E040
18: $D1E140

The 4 registers in the Lattice are at Base, Base+4, Base+8, and Base+$C, and the encoder loss bit is bit 13 on the 32-bit bus.

So for the encoder-loss bit on the last channel of the first ACC-24E2A in a typical system (i=4), you could define:

M400->u.io:$d0406C.13.1
The table was half-wrong above. Correction and completion of the table of IC index numbers and ID chip base address offsets:

4: $D06040
5: $D06140
6: $D06050
7: $D06150
8: $D0E040
9: $D0E140
10: $D0E050
11: $D0E150
12: $D16040
13: $D16140
14: $D16050
15: $D16150
16: $D1E040
17: $D1E140
18: $D1E050
19: $D1E150
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