ScratchpadClass< T, N, CAPACITY_IN_WORDS > Class Template Reference

Parameterized banked scratchpad memory implemented as a C++ class (i.e. not a SystemC module) More...

#include <Scratchpad.h>

Classes
struct	bank_req_t

Public Types
typedef cli_req_t< T, ADDR_WIDTH, N >	req_t
typedef cli_rsp_t< T, N >	rsp_t

Public Member Functions
typedef	NVUINTW (NBANKS_LOG2) bank_sel_t
typedef	NVUINTW (ADDR_WIDTH - NBANKS_LOG2) bank_addr_t
void	store (req_t req)
rsp_t	load (req_t req)
void	load_store (req_t curr_cli_req, rsp_t &load_rsp)

Public Attributes
mem_array_sep< T, CAPACITY_IN_WORDS, N >	banks
bank_req_t	input_reqs [N]
bool	input_reqs_valid [N]
bank_req_t	bank_reqs [N]
bool	bank_reqs_valid [N]
T	bank_rsps_data [N]
bool	bank_rsps_valid [N]
bool	load_rsps_valid [N]
cli_rsp_t< T, N >	load_rsp
bank_sel_t	bank_src_lane [N]
bank_sel_t	bank_dst_lane [N]

Static Public Attributes
static const int	ADDR_WIDTH = nvhls::nbits<CAPACITY_IN_WORDS - 1>::val
static const int	NBANKS_LOG2 = nvhls::nbits<N - 1>::val

Detailed Description

template<typename T, int N, int CAPACITY_IN_WORDS>
class ScratchpadClass< T, N, CAPACITY_IN_WORDS >

Parameterized banked scratchpad memory implemented as a C++ class (i.e. not a SystemC module)

Template Parameters

T	EntryType
N	Number of requests
CAPACITY_IN_WORDS	Total number of words of type T in memory

Overview

-Assumptions: All N requests are guaranteed conflict-free. An assertion message will be emitted if there are any bank conflicts.

Available Member Functions

void store(req_t req);  // Stores (ie writes) N request to banked memory
 
rsp_t load(req_t req);  // Loads (ie reads) N requests from banked memory

A Simple Example

  #include <Scratchpad.h>
  ...
  typedef ScratchpadTraits<uint32, 16, 16 * 0x1000> local_mem;
  ...
  local_mem::mem_class_t scratchpad1;  // instantiate a ScratchpadClass
  local_mem::scratchpad_req_t sp_req;  // local scratchpad request type
 
  // copy incoming request to scratchpad request
  #pragma hls_unroll yes
  for (int i=0 ; i < local_mem::num_inputs; i++)
    sp_req.set(i, req1.addr + i, req1.data[i]);
 
  if (req1.is_load)    {
    // if it is a load (i.e. read) operation, get the read data from the RAM
    local_mem::base_rsp_t rsp = scratchpad1.load(sp_req);
    // compute MAC
    local_mem::word_type sum=0;
    #pragma hls_unroll yes
    for (int i=0; i < local_mem::num_inputs; i++) {
      sum += rsp.data[i] * req1.data[i];
    }
    // Push out the sum
    out1.Push(sum);
 }
 else
 {
   // if it is a store (i.e. write) operation, write the data to the RAM
   scratchpad1.store(sp_req);
}

Usage Guidelines

This class sets the stall mode to flush by default to mitigate possible RTL bugs that can occur in the default stall mode. If you are confident that this class of bugs will not occur in your use case, you can change the stall mode via TCL directive:

directive set /path/to/ScratchpadClass/run/while -PIPELINE_STALL_MODE stall

This may reduce area/power.

Definition at line 101 of file Scratchpad.h.

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The documentation for this class was generated from the following file:

• Scratchpad.h