Executive

Description

The hs_npu_executive module serves as the interface between the PeakRDL (autogenerated) CSR module and the memory ordering unit, managing control signals and configurations for the ScaleNPU system. It processes CSR values to configure layer parameters, matrix dimensions, and memory addresses. Additionally, it manages control flags for reusing inputs, applying bias, and selecting activation functions, along with interrupt signaling. This submodule coordinates between the CSR interface and memory ordering.

This module also handles error codes and performs basic checks on the parameters passed in the CSRs, currently validating that the input size does not exceed the maximum input and output buffer size.

Note

If more error/exit codes are to be added, this module and the CSR module are the appropriate places to do so. For example, the memory interface always assumes memory does not fail. This module could connect to the memory interface and link to AXI failure signals so that, in case of a memory error, it is reported to the CPU.

I/O Table

Input Table

Input Name	Direction	Type	Description
clk	Input	logic	Clock signal for synchronization.
rst_n	Input	logic	Active-low reset signal.
hwif_out	Input	hs_npu_ctrlstatus_regs_pkg::hs_npu_ctrlstatus_regs__out_t	CSR output values for configuration and control flags.
memory_ordering_ready_i	Input	logic	Indicates readiness from the memory ordering unit for new commands.
finished	Input	logic	Signal indicating completion of the current task.

Output Table

Output Name	Direction	Type	Description
hwif_in	Output	hs_npu_ctrlstatus_regs_pkg::hs_npu_ctrlstatus_regs__in_t	CSR input signals to update internal states and trigger interrupts.
irq	Output	logic	Interrupt request signal for the CPU upon task completion.
memory_ordering_valid_o	Output	logic	Valid signal indicating new command for memory ordering unit.
num_input_rows_out	Output	uword	Number of rows in the input matrix from the CSR.
num_input_columns_out	Output	uword	Number of columns in the input matrix from the CSR.
num_weight_rows_out	Output	uword	Number of rows in the weight matrix from the CSR.
num_weight_columns_out	Output	uword	Number of columns in the weight matrix from the CSR.
reuse_inputs_out	Output	logic	Flag to reuse input data across computations.
reuse_weights_out	Output	logic	Flag to reuse weights across computations.
save_outputs_out	Output	logic	Flag to save computation outputs.
use_bias_out	Output	logic	Enables bias in the computation.
use_sum_out	Output	logic	Enables sum accumulation in the computation.
shift_amount_out	Output	uword	Shift amount for adjusting results post-computation.
activation_select_out	Output	logic	Activation function selection for computation.
base_address_out	Output	uword	Base memory address for data access.
result_address_out	Output	uword	Memory address for storing results.

Submodule Diagram

The diagram is trivial.

Related Files

File Name	Description
hs_npu_executive	Top module
hs_npu_ctrlstatus_regs	Defines CSR structure and types used by the module.

Note

The actual .sv of the CSRs is autogenerated by PeakRDL. Look within the \regblock directory inside \build to find it.