Power On Reset - MultiChip ?
Posted: Mon Jul 15, 2013 7:46 pm
I have a problem with Power On Reset on a custom made board.
I have 3 L1; each with its own power-supply and POR cuircuit but only one FLASH for boot. The 2 slaves shall boot via XLINK.
It works fine with the XTAG2 not using the flash, with the JTAG chain connecting them together.
It is possible to flash the card without any error.
Powering it on without the XTAG´s will thus result in 3 different POR, but that doesn't work - the master will never start reading the flash.
Manually resetting all chips at the same time works fine, and all cores boots.
I found this topic
http://www.xcore.com/forum/viewtopic.php?p=13744#p13744
What is the timing requirement for the reset in a multi-chip setup with independent reset?
Why does the master never start reading the FLASH? If it was a problem with the XLINK timing, I suppose it should at least read the code first prior to a failure.
I can program the POR delay so it will be released in a specific order.
I have tested a POR-time of 1.7s on the master - it didn't work - but a manual reset still works. What is the difference ?
I have 3 L1; each with its own power-supply and POR cuircuit but only one FLASH for boot. The 2 slaves shall boot via XLINK.
It works fine with the XTAG2 not using the flash, with the JTAG chain connecting them together.
It is possible to flash the card without any error.
Powering it on without the XTAG´s will thus result in 3 different POR, but that doesn't work - the master will never start reading the flash.
Manually resetting all chips at the same time works fine, and all cores boots.
I found this topic
http://www.xcore.com/forum/viewtopic.php?p=13744#p13744
What is the timing requirement for the reset in a multi-chip setup with independent reset?
Why does the master never start reading the FLASH? If it was a problem with the XLINK timing, I suppose it should at least read the code first prior to a failure.
I can program the POR delay so it will be released in a specific order.
I have tested a POR-time of 1.7s on the master - it didn't work - but a manual reset still works. What is the difference ?