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| author | Clifford Wolf <clifford@clifford.at> | 2016-03-31 07:59:55 +0200 |
|---|---|---|
| committer | Clifford Wolf <clifford@clifford.at> | 2016-03-31 07:59:55 +0200 |
| commit | cecd0cf788a7fcefe6e88c32557fd844482a1c9c (patch) | |
| tree | 8ee051eee8c695aed3d37a569de9e1d78197369b /techlibs/greenpak4/cells_sim.v | |
| parent | 0db53284fd610cac1e956a87c7eec7df3d8564c5 (diff) | |
| parent | 984561c034bac0b996d8b2201105a795c6c0e00d (diff) | |
| download | yosys-cecd0cf788a7fcefe6e88c32557fd844482a1c9c.tar.gz yosys-cecd0cf788a7fcefe6e88c32557fd844482a1c9c.tar.bz2 yosys-cecd0cf788a7fcefe6e88c32557fd844482a1c9c.zip | |
Merge pull request #142 from azonenberg/master
Add initial GreenPak4 counter inference, misc related fixes
Diffstat (limited to 'techlibs/greenpak4/cells_sim.v')
| -rw-r--r-- | techlibs/greenpak4/cells_sim.v | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/techlibs/greenpak4/cells_sim.v b/techlibs/greenpak4/cells_sim.v index 3acea01d2..2727d9246 100644 --- a/techlibs/greenpak4/cells_sim.v +++ b/techlibs/greenpak4/cells_sim.v @@ -91,6 +91,33 @@ module GP_COUNT8(input CLK, input wire RST, output reg OUT); parameter CLKIN_DIVIDE = 1; //more complex hard IP blocks are not supported for simulation yet + + reg[7:0] count = COUNT_TO; + + //Combinatorially output whenever we wrap low + always @(*) begin + OUT <= (count == 8'h0); + end + + //POR or SYSRST reset value is COUNT_TO. Datasheet is unclear but conversations w/ Silego confirm. + //Runtime reset value is clearly 0 except in count/FSM cells where it's configurable but we leave at 0 for now. + //Datasheet seems to indicate that reset is asynchronous, but for now we model as sync due to Yosys issues... + always @(posedge CLK) begin + + count <= count - 1'd1; + + if(count == 0) + count <= COUNT_MAX; + + /* + if((RESET_MODE == "RISING") && RST) + count <= 0; + if((RESET_MODE == "FALLING") && !RST) + count <= 0; + if((RESET_MODE == "BOTH") && RST) + count <= 0; + */ + end endmodule |