Entity: spid_readbuffer

• File: spid_readbuffer.sv

Diagram

Description

Generics

Generic name	Type	Value	Description
ReadBufferDepth	int unsigned	spi_device_pkg::SramMsgDepth	Buffer size: # of indices assigned to Read Buffer. This is used to calculate double buffering and threshold.
BufferAw	int unsigned	$clog2(ReadBufferDepth)	Derived parameters

Ports

Port name	Direction	Type	Description
clk_i	input
rst_ni	input
sys_rst_ni	input		to keep the addr, bufidx, flip signals
current_address_i	input	[31:0]
threshold_i	input	[BufferAw:0]	A buffer size among two buffers (in bytes)
sfdp_hit_i	input
mailbox_hit_i	input
mailbox_en_i	input
start_i	input		start: data Output phase indicator. Either pulse or level are fine.
event_watermark_o	output
event_flip_o	output

Signals

Name	Type	Description
st_q	st_e
st_d	st_e
watermark_cross	logic	////////// Signal // //////////
watermark_crossed	logic	set by event / clear by flip
flip	logic
next_buffer_addr	logic [31-OneBufferAw:0]	The logic keeps next buffer address. Compare this with the current_address and if it hits with mask, then the flip event occurs. TODO: If the device goes sleep, the next_buffer_addr should be recoverable.
active	logic
current_buffer_idx	logic [31-OneBufferAw:0]

Constants

Name	Type	Value	Description
BufferAw	int unsigned	$clog2(ReadBufferDepth)	Derived parameters
BufferSize	int unsigned	ReadBufferDepth	////////////// Definition // //////////////
OneBufferSize	int unsigned	BufferSize / 2	bytes
OneBufferAw	int unsigned	$clog2(OneBufferSize)

Types

Name	Type	Description
st_e	enum logic { StIdle, StActive }

Processes

• unnamed: ( @(posedge clk_i or negedge sys_rst_ni) )

• unnamed: ( @(posedge clk_i or negedge sys_rst_ni) )

• unnamed: ( @(posedge clk_i or negedge rst_ni) )

• unnamed: ( )