A question about the IRQ pin of MPC8308, Please help us!

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

A question about the IRQ pin of MPC8308, Please help us!

421 Views
pdwang
Contributor II

Dear Sir:

     We designed a circuit board based on MPC8308, because we don't use IRQ1 and IRQ3 of MPC8308, we leave the IRQ1# and IRQ3# pins of MPC8308 unconnected (we didn't connect pull-up resistors). Is this a serious problem? Will it make the MPC8308 abnormal ? Thanks!

     We had downloaded u-boot.bin into NOR flash on our board, but the u-boot can't boot. So we suspect if it relates to the unconnected IRQ pins of MPC8308.

1 Reply

340 Views
LPP
NXP Employee
NXP Employee

Reset state of SEMSR[IRQn] disables external interrupts.

So, the state of IRQ1, IRQ3 signals should not cause problems unless the software unmasks these interrupts.

Note:

"To ensure reliable operation, it is highly recommended to connect unused inputs to an appropriate signal level. Unused active low inputs should be tied to NVDD, GVDD, LVDD as required. Unused active high inputs should be connected to VSS. All NC (no-connect) signals must remain unconnected."


Have a great day,
Pavel

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------