AxiSpiMaster - Fix bug in shadow RAM for multi-chip configurations #1205
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
ruck314
reviewed
Oct 7, 2024
| @@ -55,8 +55,8 @@ entity AxiSpiMaster is | |||
| axiWriteMaster : in AxiLiteWriteMasterType; | |||
| axiWriteSlave : out AxiLiteWriteSlaveType; | |||
| -- Copy of the shadow memory (SHADOW_EN_G=true) | |||
| shadowAddr : in slv(ADDRESS_SIZE_G-1 downto 0) := (others => '0'); | |||
| shadowData : out slv(DATA_SIZE_G-1 downto 0) := (others => '0'); | |||
| shadowAddr : in slv(log2(SPI_NUM_CHIPS_G)+ADDRESS_SIZE_G-1 downto 0) := (others => '0'); | |||
There was a problem hiding this comment.
@bengineerd Should you use BitSize (instead of log2()) here?
There was a problem hiding this comment.
As it turns out neither log2 nor bitSize are correct. We want the function to return 0 when given SPI_NUM_CHIPS_G=1. Otherwise shadowAddr will be one bit larger than it was before and break builds. I will fix it.
There was a problem hiding this comment.
Unless we just want to update the one and only application that uses shadowAddr.
https://github.com/slaclab/amc-carrier-core/blob/21ce13174561512fc1ec0e2fb1d071eb8db88381/AppHardware/RtmCryoDet/rtl/RtmCryoDet.vhd#L527
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Description
The
SHADOW_EN_Gfeature that reads from a shadow RAM was broken for cases whenSPI_NUM_CHIPS_G > 1.It would use the same shadow RAM of all chips. The RAM size has been increased so that there is a separate address space in the RAM for each chip.