This is a CPU core based on the RISC-V ISA reduced in size to support 16-bit data and memory operations with 21-bit instructions and 16 registers. The full RISC-V base instruction set is supported with the exception of the CSRs which were removed. The design uses a Harvard memory architecture. The design project evolved from a submission for the Tiny Tapeout project where an 8-bit processor was implemented. The external memory interface for the chip employs a simple serdes to accomodate the limited I/O pins available. This reduces the effective processor clock by 8x in order to synchronize the instruction and data memory interfaces. This was a compromise that evolved as a solution to interface the chip to the larger I/O interface of the processor core.
Inputs:
- clock
- reset
- enable
- imem_rdy
- dmem_bsy
- dmem_rdy
- serdes input bit 0
- serdes input bit 1
- serdes input bit 2
- serdes input bit 3
- serdes input bit 4
- serdes input bit 5
- serdes input bit 6
- serdes input bit 7
- serdes input bit 8
- serdes input bit 9
- serdes input bit 10
- serdes input bit 11
- serdes input bit 12
Outputs:
- halt
- dmem_we
- dmem_en
- serdes output bit 0
- serdes output bit 1
- serdes output bit 2
- serdes output bit 3
- serdes output bit 4
- serdes output bit 5
- serdes output bit 6
- serdes output bit 7
- serdes output bit 8
- serdes output bit 9
- serdes output bit 10
- serdes output bit 11
- serdes output bit 12
- serdes output bit 13
- serdes output bit 14
- serdes output bit 15
(Below are the original instructions used to submit the design.)
Template for submitting TinyTapeout based projects to the Open MPW shuttle program.
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Generate a new project based on this template
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Set GitHub Pages
Sources
asGitHub Actions
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Create a new Wokwi project.
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Update
info.yaml
with yourwokwi_id
and make sure thedocumentation
forinputs
andoutputs
matches the Wokwi design. -
Commit, push and check the workflow summary (if successful a new commit including the hardened files will be automatically created).
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Submit your project github repository to the next Open MPW shuttle.