GR740-UM-DS, Nov 2017, Version 1.7
484
www.cobham.com/gaisler
GR740
43.2.7 Temperature sensor
The on-chip temperature sensor does not have its power supply connected in the current version of the
device.
Workaround:
None.
Applicable to:
This issue is addressed in package revision (note package, not silicon) 1.
43.2.8 LVDS driver ESD sensitivity at low voltage HBM
The ESD protection structure for the LVDS output pins on the prototype device, which are spw_txd,
spw_txs and mem_clk_out_diff) has been found to exhibit failures at low voltage below 2KV while
passing tests performed according to JEDEC standard (ANSI/ESDA/JEDEC JS-001-2012) at 2KV
and 4KV.
Please contact Cobham Gaisler for further information on this issue.
Workaround:
The issue can be mitigated on board level by adding external LVDS transceivers. Pre-
cautions need to be taken when handling the devices.
Applicable to:
This issue is only present in silicon revision 0.
43.2.9 LEON4 store operation malfunction with MMU TLB disabled
When the MMU is enabled and the MMU TLB is disabled then an incorrect address can be generated
for store operations. The default value after reset is to have the TLB enabled and designs that keep the
TLB enabled are not affected.
Workaround:
Do not disable the TLB when the MMU is enabled. The TLB is normally only dis-
abled for debugging purposes and operating systems keep the TLB enabled.
Applicable to:
This issue is only present in silicon revision 0.
43.2.10 LEON4 break on RETT instruction
Processor execution would not resume correctly when starting execution on a RETT instruction.
The hardware fix implemented for this avoid stopping execution on RETT instructions.
Workaround:
Avoid placing breakpoints (hardware and software) on RETT instructions. Do not sin-
gle-step over RETT instructions.
Applicable to:
This issue is only present in silicon revision 0. Software may still not insert break-
points (and then start execution) on RETT instructions.
43.2.11 DSU4 instruction cache diagnostic burst access
Diagnostic instruction cache accesses should not be performed using bursts to the DSU4 interface
since this will lead to bad data being read from the interface.
Workaround:
Do not use the Ethernet debug link to perform diagnostic accesses to the instruction
cache.
Applicable to:
This issue is only present in silicon revision 0.
43.2.12 Interrupt controller monitor/boot interface change
The interrupt controller can be used to start processor execution from a specified start address. The
interface to accomplish this is different between GR740 silicon revision 0 and silicon revision 1.
In GR740 revision 0, the following registers are available:
•
Processor reset start address registers for processors 0 - 3
•
Processor boot register