Hi.
A question regarding boot sequence for AM3352, used with TPS65910 and DDR3, plus 8 bit NAND MT29F2G08ABAE for boot and linux file system.
The TMDSSK3358 has SYSBOOT[4:0] = 10111b which will yield the following boot sequence:
MMC0, SPI0, UART0, USB0
In our design, we believe we would like something in the order of;
NAND, MMC0, EMAC1, UART0
or
NAND, EMAC1, MMC0, UART0
The MMC0 option is mandatory the first time the pcb boots, when the NAND should be programmed for further boots.
The eventual closest (?) existing option is;
a) NAND, NANDI2C, MMC0, UART0
Better (in the sense that we should also enable the usage of ethernet boot, this is though not mandatory) would perhaps be the other existing;
b) NANDI2C, MMC0, EMAC1, UART0
Questions;
In case a), pcb should normally have all it needs in NAND and the boot should be quick and good.
If there is no NAND (= not programmed, pcb coming from factory), the boot sequence should eventually time out and get to the MMC0.
How long time (to skip NAND and NANDI2C) should this take approximately?
This is only important the first time the pcb is booted and the NAND should get programmed. But the waiting time is though a factor in the process.
Case b) is closest to the alternative we *believe* we should have most benefit from. But then we should need to store flash parameters in I2C.
Now the board do have an I2C memory, aimed to be used for user settings and event log.
Should there be any problem to use some (as much as needed) of its address space for the NANDI2C data?
Tnx / Peter
