Description
Warning: [214-353] Could not widen since type
i512 size is greater than or equal to the
max_widen_bitwidth
threshold of 512.Explanation
Vitis HLS has determined that the given port's width can be
automatically widened but is prevented from doing so by the setting of the
max_widen_bitwidth parameter.
The rules for the auto port-width widening algorithm is as follows:
- The
max_widen_bitwidthvalue should be in the range [0, 1024], and it must be either 0 or a power of 2. If this rule is not satisfied, Vitis HLSwill ignore this value. - If ports are bundled together, one bundle name can have only one
max_widen_bitwidthvalue. If multiple values are specified by the user, the max value will be selected.
There are three ways of defining this parameter. They are as follows:
[Option 1] Pragma specification
void top(ap_int<32> *a, ap_int<32> *b, ap_int<32> *c) {
#pragma HLS INTERFACE m_axi port=a max_widen_bitwidth=256
}
[Option 2] Directive specification
set_directive_interface -mode m_axi -max_widen_bitwidth 256 top a
[Option 3] config_interface -m_axi_max_widen_bitwidth 512
(default value is 512 in Vitis kernel flow while it is 0 in Vivado IP flow)