Control Unit.md

Control Unit Implementation

Overview

The Control Unit orchestrates the 2D convolution operation on a systolic array architecture. data movement between DRAM, SRAM, and the systolic array.

State Machine

State	Description
IDLE	Waiting for start signal
CONFIG	Configure data loader with N and K parameters
LOAD_DATA_TO_SRAM	Load image and kernel from DRAM to SRAM
LOAD_K_TO_SA	Initiate kernel loading to systolic array
WAIT_LOAD_K_TO_SA	Wait for kernel loading completion
COMPUTE	Process convolution by streaming columns through SA
STORE_OUT	Write results to DRAM
DONE_STATE	Signal completion

Signal Interface

Configuration & Control

Signal	Direction	Width	Source → Destination	Active When	Description
start	IN	1	Top → CU	IDLE	Initiate computation
cfg_N	IN	7	Top → CU	CONFIG	Image dimension
cfg_K	IN	5	Top → CU	CONFIG	Kernel dimension
done	OUT	1	CU → Top	DONE_STATE	Computation complete flag

Data Loader Interface

Signal	Direction	Width	Source → Destination	Active When	Description
dl_cfg_N	OUT	7	CU → Data Loader	CONFIG	Pass N to data loader
dl_cfg_K	OUT	5	CU → Data Loader	CONFIG	Pass K to data loader
start_loading_data_to_sram	OUT	1	CU → Data Loader	LOAD_DATA_TO_SRAM	Begin loading image/kernel from DRAM
done_loading_data_to_sram	IN	1	Data Loader → CU	LOAD_DATA_TO_SRAM	Data loading completed
start_pass_dl	OUT	1	CU → Data Loader	LOAD_K_TO_SA	Pulse to initiate data loader kernel pass
dl_output_data_valid	IN	1	Data Loader → CU	COMPUTE	Data from loader is valid

Kernel Loading

Signal	Direction	Width	Source → Destination	Active When	Description
load_kernel	OUT	1	CU → SA Controller	LOAD_K_TO_SA	Command to load kernel to SA
kernel_index	OUT	2	CU → SA Controller	K > SA_DIM	Identifies which kernel quadrant (0-3)
done_loading_kernel_to_sa	IN	1	SA Controller → CU	WAIT_LOAD_K_TO_SA	Kernel loaded into SA