Sakura-IT / Prometheus

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Specific data send to Bigfoot Killer 2100 memory gets dropped by MPC8314E's CSB PCIe Bridge #2

Open DvdBoon opened 7 months ago

DvdBoon commented 7 months ago

Specific data send by the 68K to Prometheus over the PCIe bridge to the PCIe Bigfoot card gets dropped.

This is not address specific but data specific and 100% reproducable.

The following error bit is flagged: PEX_CSB_IBSTAT_BRGER = 1

For byte transfers, the following data is lost and the MPC8314E indicates an error on CSB inbound transfer (tested from $00-$C0, i guess I should test till $FF):

$31, $32, $34, $37, $38, $3B, $3D, $3E

Word transfers and longword transfers are harder to predict which ones get dropped, but at least a very vital longword gets dropped which is used in the reset procedure:

$52535445

Old data remains in the memory location the write was supposed to go. It does not lock the card and data can be continued to be send.

Another example; At a location the inital data is 0,0,0,0 in longwords. Writing the following longwords:

$806001E4, $38630001, $906001E4, $4BFFFFF4

Gives the following result: $806001E4, $00000000, $906001E4, $4BFFFFF4

With further tests just writing $38630001 anywhere in the address range, the results are always that this longword gets dropped with a CSB inbound error.

DvdBoon commented 7 months ago

I am pretty sure this is a HW issue. But just putting it here just in case.

DvdBoon commented 7 months ago

Data is not dropped when using Xilinx chips with vhdl firmware. Checking to see if we can update/fix the Altera firmware.

Apparently also the pci variant of M1/K1 work with the Xilinx firmware without crashing in Warp3D

DvdBoon commented 6 months ago

E3B will be providing the source of the Altera firmware. Hopefully a solution will be found