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Which pins of Cortex-M3 and Cortex-M4 can be excluded from toggle coverage?

Applies to: Cortex-M3, Cortex-M4

Scenario

The intended audience of this knowledge article are verification engineers running test simulation on a Cortex-M3 or Cortex-M4 based SoC design.

Answer

The following tables contain the output pins on the Cortex-M3 and Cortex-M4 module boundary where it is expected not to see the pin values to change during simulation, therefore these pins can be safely excluded from toggle coverage in verification.

I-Code interface

Signal Bits Comment
HADDRI [31:29] Only addresses between 0x00000000 - 0x1FFFFFFF accessed on this interface
HADDRI[31:29] : Always 3'b000
HADDRI [1:0] All accesses on this interface are WORD aligned
HADDRI[1:0] : Always 2'b00
HTRANSI [0] All accesses on this interface performed as
2'b00 = IDLE
2'b10 = NONSEQUENTIAL
HSIZEI [2:0] All accesses on this interface performed as
3'b010 = WORD
HBURSTI [2:0] All accesses on this interface performed as
3'b000 = SINGLE
HPROTI [3:2] HPROTI[2] : Always 0 = NONBUFFERABLE
HPROTI[3] : Always 1 = CACHEABLE
MEMATTRI [1:0] MEMATTRI[0] : Always 0 = NONALLOCATE
MEMATTRI[1] : Always 0 = NONSHAREABLE

D-Code interface

Signal Bits Comment
HADDRD [31:29] Only addresses between 0x00000000 - 0x1FFFFFFF accessed on this interface
HADDRD[31:29] : Always 3'b000
HSIZED [2] All accesses on this interface performed as
3'b000 = BYTE
3'b001 = HALFWORD
3'b010 = WORD
HBURSTD [2:1] All accesses on this interface performed as
3'b000 = SINGLE
3'b001 = INCR
HPROTD [3:2],[0] HPROTD[0] : Always 1 = DATA ACCESS
HPROTD[2] : Always 0 = NONBUFFERABLE
HPROTD[3] : Always 1 = CACHEABLE
MEMATTRD [1:0] MEMATTRD[0] : Always 1 = ALLOCATE
MEMATTRD[1] : Always 0 = NONSHAREABLE

System interface

Signal Bits Comment
HSIZES [2] All accesses on this interface performed as
3'b000 = BYTE
3'b001 = HALFWORD
3'b010 = WORD
HBURSTS [2:1] All accesses on this interface performed as
3'b000 = SINGLE
3'b001 = INCR

HTM interface

Signal Bits Comment
HTMDHSIZE [2] Accesses can be
3'b000 = BYTE
3'b001 = HALFWORD
3'b010 = WORD

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