PartitionedSignal is a dynamic SIMD version of Signal. it has a partition "context" associated with it which is also a Signal. 32 bit partitioned signal: ppts: 1 2 3 sig : 0xNN 0xNN 0xNN 0xNN this 32 bit PartitionedSignal may be 1x32, 2x16, 4x8, or any other permutation including 24-8. Array accesses of Signals work very simply by allocating a pmux. a = Array([Signal(4), Signal(4)]) b = Signal(2) a[b].eq(5) however Array has no concept of PartitionedSignal and will completely fail to produce the right action. ppts = PartitionPoints(4) a = Array([PartitionedSignal(16, ppts), PartitionedSignal(16, ppts)]) b = PartitionedSignal(8, ppts) a[b].eq(5) # fails the reason this fails is because "b" is not a Signal of 8 bits, it is *dynamically interpreted* depending on the current context at runtime of its partition. example: * the partition may be set to "all closed", indicating that b is 4x 2-bit AND * a Array items are 4x 4-bit Then if: * first part of b may be 0b00 * second part of b may be 0b01 * third part of b may be 0b01 * first part of b may be 0b00 this indicates that ***FOUR*** separate and distinct pmux operations shall take place, ***NOT*** one, as follows: * a[0b00][0:3].eq(5) # from 1st b part * a[0b01][4:7].eq(5) # from 2nd b part * a[0b01][8:11].eq(5) # from 3rd b part * a[0b00][12:15].eq(5) # from 4th b part this because the partition is set to 4x 4 bit and therefore a's PartitionedSignals are treated as 4 completely independent 4 bit Arrays (i.e. they are SIMD) if however the partitions are 8-8 and b is as follows * b first part is 0b0000 * b second part is 0b0001 then: * a[0b0000][0:7].eq(5) # from 1st b * a[0b0001][8:15].eq(5) # from 2nd b this because b is now subdivided into 2x 4 bit parts, therefore when used as an array index it splits A elements into 2x 8 bit ***INDEPENDENTLY INDEXED*** parallel 8 bit SIMD arrays. lastly and only if the partitions are entirely open (clear) may the array a and the index b be considered "scalar signals" * b may be set to 0b00000001 therefore the following is actioned: * a[0b00000001][0:15].eq(5) the assignment RHS may also be another PartitionedSignal (only ever with the same partition context) and consequently the parts of a on LHS are dynamically assigned the parts of the RHS. at no time may partition contexts be shared (mixed)

this task is ridiculously complex (mind-bendingly so) and involves a deep understanding of ArrayProxy. it's temporarily off the list for now.