Default MQX_HARDWARE_INTERRUPT_LEVEL_MAX for K70?

[mjosborne]

Hello,

we're using MQX 4.1 with the K70 and have taken a look at the MQX User Guide section 3.9.3.4.

Out of the box BSP_DEFAULT_MQX_HARDWARE_INTERRUPT_LEVEL_MAX = 2.

We were wondering why this value was chosen as a default?

In general we assume that all our tasks can be interrupted by an IRQ.

For the most part we let MQX manage our interrupts; but we do have the odd occasion to install a kernel interrupt when necessary.

We're thinking of changing BSP_DEFAULT_MQX_HARDWARE_INTERRUPT_LEVEL_MAX = 7; we don't have any tasks with priorities less than 2.

Are there any consequences to this besides ensuring that our tasks can always be interrupted?

Thanks for the help,

Matt

[soledad]

Hello Matt,

BSP_DEFAULT_MQX_HARDWARE_INTERRUPT_LEVEL_MAX is used during MQX initialization to set MQX_HARDWARE_INTERRUPT_LEVEL_MAX, which is described in the MQX User Guide document in section 3.9.3.4.

It lets a user re-configure MQX so that when a MQX task is running, it leaves some interrupt levels still enabled so that any interrupt below that level will act like a NMI and execute asynchronously to MQX kernel execution. Table 3-46 shows this relationship.

Typically this value is not changed, and can cause some odd things to happen if some interrupt priorities are not configured correctly.

Have a great day,
Sol

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