Blocking API
The term blocking means that operation stalls until fresh data is available on the Direct I/O channels. The blocking API automatically checks if the Direct I/O variable has any input data.
Blocking Writes
This method .write() writes the value "counter" to the Direct I/O variable "reset_value".
// usage of void write( const T &din)
dut_top(hls::ap_vld<int> &reset_value,..)
...
reset_value.write(counter);
..The << operator is overloaded such that it can be used in a similar
fashion to the stream insertion operators for C++ stream (for example, iostreams and
filestreams). The hls::ap_vld/ap_hs/ap_none<>
object to be written to is supplied as the left-hand side argument and the value to be
written as the right-hand side.
// usage of void operator << (_const T & din) {
dut_top(hls::ap_vld<int> &reset_value,..)
...
reset_value << counter;
..Blocking Reads
This <var>.read()method reads from
the "reset_myCounter" and assigns the values to the variable reset.
// usage of void read(const T & dout)
void krnl_stream_vdatamover(...
hls::ap_hs<int> &reset_myCounter
) {
...
int reset = reset_myCounter.read();
...
}The >> operator is overloaded such that it can be used in a similar
fashion to the stream insertion operators for C++ stream (for example, iostreams and
filestreams). The hls::ap_vld/ap_hs/ap_none<>
object to be read is supplied as the LHS argument, and the destination variable is the
RHS.
// Usage of void operator >> (const T& rdata) void krnl_stream_vdatamover(..., hls::ap_hs<int> &reset_myCounter ){
...
reset_myCounter >> reset;
...
}Non-blocking API
The term non-blocking means that lack of data (or too much data) on the
stream does not block the operation of a function or the iteration of a loop.
Non-blocking methods return a Boolean value indicating the status of a read or write:
true if successful, false otherwise.
Non-blocking Write
This method is supported for ap_hs/ap_vld which attempts to push data
into the stream, returning a Boolean true if
successful. Otherwise, false is returned.
// usage of bool write_nb(const T_& din)
dut_top(hls::ap_vld<int> &reset_value,..)
int counter =1;
reset_value.write_nb(counter);The << operator is overloaded such that it can be used in a similar
fashion to the stream insertion operators for C++ stream (for example, iostreams and
filestreams). The hls::ap_vld/ap_hs/ap_none<>
object to be written to is supplied as the left-hand side argument and the value to be
written as the right-hand side.
// usage of void operator << (_const T & din) {
dut_top(hls::ap_vld<int> &reset_value,..)
...
reset_value << counter;
..Non-blocking Read
This method is supported for ap_hs/ap_vld which attempts to push data
into the stream, returning a Boolean true if
successful. Otherwise, false is returned.
// Usage of bool read_nb(__STREAM_T__& dout)
hls::ap_vld<int> &reset_myCounterint reset =1; reset_myCounter.read_nb(reset);The >> operator is overloaded such that it can be used in a similar
fashion to the stream insertion operators for C++ stream (for example, iostreams and
filestreams). The hls::ap_vld/ap_hs/ap_none<>
object to be read is supplied as the LHS argument, and the destination variable is the
RHS.
// Usage of void operator >> (const T& rdata)
void krnl_stream_vdatamover(..., hls::ap_hs<int> &reset_myCounter ){
...
reset_myCounter >> reset;
...
}