Design fails co-sim when using DATAFLOW directive

Question

hi, there's a function in my design that i want to turn on the DATAFLOW directive,
but whenever i do so the co-simulation fails,
and HLS warns that the RTL produces 'X' values.
the function looks like this:
void appKernel(const uint32_t in_buf[ROWS][COLS],
const uint32_t in2_buf[ROWS][COLS], uint32_t out_buf[ROWS][COLS]) {
#pragma HLS ARRAY_RESHAPE variable=out_buf complete dim=2
#pragma HLS ARRAY_RESHAPE variable=in2_buf complete dim=2
#pragma HLS ARRAY_RESHAPE variable=in_buf complete dim=2
#pragma HLS DATAFLOW
#pragma HLS INLINE off
uint32_t aryA_size;
uint32_t aryB_size;
uint32_t aryC_size;
double aryA[ARY_ROWS][ARY_COLS];
#pragma HLS ARRAY_RESHAPE variable=aryA complete dim=2
double aryB[ARY_ROWS][ARY_COLS];
#pragma HLS ARRAY_RESHAPE variable=aryB complete dim=2
double aryC[ARY_ROWS][ARY_COLS];
#pragma HLS ARRAY_RESHAPE variable=aryC complete dim=2
pre_process(in_buf, aryA_size, aryA);
pre_process(in2_buf, aryB_size, aryB);
linearR(aryA_size, aryA, aryB_size, aryB, aryC_size, aryC);
post_process(aryC_size, aryC, out_buf);
After looking into the trace waveform i found this:
You can see that the "aryC" ping-pong buffer was written into it 'X' values at the addr 22.
However at the upper part of waveform, the ap_start, ap_continue, ap_done handshakes for "linearR" looks fine.
Also, the design works correctly when DATAFLOW was not used.
The "linearR" function at its end writes to "aryC" in a for loop that looks like this:
loop_ary_rows: for (int i = 0; i < num_beat; i++) {
#pragma HLS PIPELINE II=1
#pragma HLS LOOP_TRIPCOUNT min=1 max=32
loop_ary_cols: for (int j = 0; j < ARY_COLS; j++) {
a[j + 3] = aryA[i + 1][j];
b[j] = aryB[i][j];
if (a[j] == b[j])
aryC[i][j] = 5.0;
else
aryC[i][j] = 7.0;
a[0] = a[4];
a[1] = a[5];
a[2] = a[6];
So, what is wrong and how do i go about debugging it ?

Answer 1

Hi ,
2014.4 is not the latest one. We have released 2015.1 & now the latest one is 2015.2.
Yes, 2015.2 is much stable compared to 2014.4. Please check in 2015.2. I can check for you in 2015.2. Please attach the archived project here.