User guide

AIV-HM76V1FL Series User Manual

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Syntax: i32 getCanMask(struct CanMask *mask)

Description:

This function gets the current setting of the acceptance

masks. Masks are used to determine which bits in the

ID eld of the CAN packet are examined with the lters.

There are two acceptance masks (mask0 and mask1)

and six acceptance lters (lter0 ~ lter5) in the CAN Bus

subsystem. Filter0 ~ lter1 are associated with mask0.

Filter2 ~ lter4 are associated with mask1.

Here is the Mask/Filter truth table:

Mask bit n Filter bit n Message ID

bit n

Accept or

reject bit n

0 x x Accept

1 0 0 Accept

1 0 1 Reject

1 1 0 Reject

1 1 1 Accept

Note: x = don’t care

Parameters:

This parameter ‘mask’ is a pointer to a variable of type

‘CanMask’. Users use the eld ‘maskId’ to indicate the

mask they want and the API put the setting of the mask in

the ‘mask’ eld.

struct CanMask {

u8 maskId; // 0 or 1

u32 mask;

}

Return Value:

If this function receives the mask setting successfully, it

returns 0, any other returned value stands for error.

For example:

struct CanMask a_mask;

a_mask.maskId = 0; // indicate the mask0

i32 result;

result = getCanMask(&a_mask); // The setting of the

mask is put at

// a_mask.mask

if( result != 0)

printf(“Fail to get mask!\n”);