multidimensional ports in IPXact

[Khushi]

Hello

I have in RTL a  port like

input [A-1:0][B-1:0] port [C-1:0][D-1:0]

and in bus interface I have 4 logical signals S1 is of width A, S2 of width B, S3 of width C and S4 of width D. In this case how I can specify the portMap section.

1. In portMap, for 1 D packed array I can use ipxact:range (left/right). What about 2D packed array

2.In portMap, for 1 D un packed array, can I use indices ? what about 2D unpacked array. 

Thanks

Khushi

[kock]

Hi Kushi,

In 1685-2014, the portMap element contains a physicalPort element with a partSelect element. The partSelect element contains an indices element which you need to use for this case. The indices element contains one or more index element. Each index element corresponds to dimension in a multi-dimensional object. In your example, the RTL port has 4 dimensions of which 2 are unpacked and 2 are packed. The unpacked dimensions are represented in IP-XACT as arrays. The packed dimensions are represented as vectors. A sequence of index elements accounts for the array (unpacked) elements first and then for the vector (packed) elements. The optional range element in the partSelect element applies to the multidimensional object after the indices have been applied. So for example, a partSelect with 2 indices with values c and d represents array element port[c][d]. If you add a 3rd index with value a, then you select port[c][d][a] which represents B bits. You can select a slice of these B bits using the optional range element. You may also select a slice of the packed A*B bits with only indices c and d. In IP-XACT, you may also "linearize" the array (packed) bits. So the range element can be used to describe a slice of the C*D*A*B bits because it is known how these physical bits are logically ordered (in this case, the indices element is not used). Please see also Section B.1.7 in the 1685-2014 standard.

Best regards,
Erwin