In our application SBC1 & SBC2 of below configuration are
connected for point to point communication via FCC3 100 BaseFx
Fiber Ethernet port.
As per our application SBC1 has to transfer 250KB of data to
other SBC2 within 100msec via FCC3 link regularly at every 100 msec.
During this process FCC3 Transmitter is encountering Tx
underrun errors, on an average 1 or 2 frames per second,
at the other end, receiver is getting equal number of Rx CRC errors.
if these errors are ignored and continue to run the application,
after some time (few hours), a flood of tx underrun errors are
generated suddenly and eventually leads to total link failure of FCC3 ethernet port.
If the data size is further increased then the failure comes too
early in above case.
We have verified all TX & RX buffer descriptors for FCC1, FCC2
& FCC3 and seems to be OK.
We are unable to trace the root cause of this issue.
We are also suspecting partial crash of CPM or any timing errors.
Please help us to resolve the issue.
MPC8260 SBC configuration:
MPC8260ACZUMIBB based SBC which has FCC1, FCC2, & FCC3 configured in Ethernet mode,
SCC & MCC are not connected at all, 60x Bus configured in single mode and
interfaced to FLASH(16MB + 16MB), SRAM(1 MB) and SDRAM(128MB).
Clocks: Core -266 MHz, CPM - 200 MHz and Bus - 66 MHz
FCC1 --- 10/100 baseT PHY
FCC2 --- 10/100 baseT PHY
FCC3 --- 100 baseFx PHY (Fiber optic)
FCCn Buffer descripters are located in DPRAM and Data Buffers
are in 60x Bus SDRAM.