[SOLVED] Simple DFF in Liberty Library

[trav1s]

I am trying to synthesize using SOC Encounter, but I am faced with the following error.

Error : Unable to map design without a suitable flip-flop. [MAP-2] [synthesize ]
: Instance 'U_DIV12/clk_count_reg[0]' requires a simple flip-flop.
: Check the libraries for necessary flop cell. The cell could be marked unusable.


I don't understand why it won't accept my library entry for the simple DFF. Here is what I have:

cell(dff) {
area : 1;
pin (CLK) {
direction : input;
capacitance : 1;
}
pin (D) {
nextstate_type : data;
direction : input;
capacitance : 1;
}
/* ff/latch format */
ff (IQ) {
next_state : "D" ;
clocked_on : "CLK" ;
}
/* statetable format */
statetable(" D CLK", "IQ") {
table : " H/L R : - : H/L,\
- ~R : - : N";
}
pin(Q) {
direction : output ;
function:"IQ";
}
}


Can anyone tell me what is wrong with this syntax? Why will Encounter not accept this cell?

 

[jpvSoccer]

Hi, do you have any timing arcs in the model?

 

[trav1s]

Yes, that was the problem. For those with similar troubles it has been corrected to the following:


cell(dff_c2mosD) {
area : 32.32;
cell_leakage_power : 5.9;
cell_footprint : "dff_c2mosD"
pin (C) {
direction : input;
capacitance : 5.25;
fanout_load : 4.5;
}
pin (D) {
direction : input;
capacitance : 1.32;
fanout_load : 1;
timing () {
related_pin : "C" ;
timing_type : hold_rising;
intrinsic_rise : -600;
intrinsic_fall : -600;
}
timing () {
related_pin : "C" ;
timing_type : setup_rising ;
intrinsic_rise : 900;
intrinsic_fall : 900;
}
}

ff (IQ, InQ) {
next_state: "D";
clocked_on: "C";
}
pin(Q) {
direction : output ;
max_capacitance : 8.2 ;
max_fanout : 7 ;
function : "IQ";
timing(){
timing_type : rising_edge;
intrinsic_rise: 870;
intrinsic_fall: 1930;
rise_resistance:169;
fall_resistance:93;
related_pin : "C" ;
}
}
pin(nQ) {
direction : output ;
max_capacitance : 5.8 ;
max_fanout : 5 ;
function : "InQ";
timing(){
timing_type : rising_edge;
intrinsic_rise: 1170;
intrinsic_fall: 260;
rise_resistance:585;
fall_resistance:207;
related_pin : "C" ;
}
}
}/* end of dff_c2mosD*/