nmigen-learning/fpga/icebreaker_vga.dg

52 lines
1.8 KiB
Plaintext

import "/nmigen/lib/cdc/ResetSynchronizer"
import "/nmigen_boards.icebreaker/ICEBreakerPlatform"
import "/nmigen_dg/*"
import "/sys"
import "resources/pmod"
Top = subclass Elaboratable where
elaborate = platform ~> m where with m = Module! =>
reset = if
platform.default_rst => platform.request platform.default_rst
otherwise => Const 0
# setup clock
clk40 = Signal!
pll_lock = Signal!
Submodule.pll$ Instance "SB_PLL40_PAD" # "SB_PLL40_CORE"
i_PACKAGEPIN : (platform.request "clk12" dir:"-") # i_REFERENCECLK
i_BYPASS : (Const 0)
i_RESETB : ~reset
o_LOCK : pll_lock
o_PLLOUTGLOBAL : clk40
# icepll -o 40
p_FEEDBACK_PATH : "SIMPLE"
p_FILTER_RANGE : 1
p_DIVR : 0
p_DIVF : 52
p_DIVQ : 4
#m.domains.sync = ClockDomain "sync"
Domains.sync = ClockDomain "sync"
Comb$ ClockSignal "sync" :== clk40
Submodule$ ResetSynchronizer ~pll_lock domain: "sync"
state = Signal!
counter = Signal$ range (int plat.default_clk_frequency)
Sync$ counter :== counter - 1
When (counter==0) $ ->
Sync$ counter :== (int plat.default_clk_frequency)
Sync$ state :== ~state
Comb$ platform.request "led_r" :== state # blinks at 1hz with default clk, but way faster when at 40MHz
Comb$ platform.request "led_g" :== ~state # blinks at 1hz with default clk, but way faster when at 40MHz
if __name__ == "__main__" =>
plat = ICEBreakerPlatform!
plat.add_resources$ pmod.dvi_12bit 0
plat.add_resources$ plat.break_off_pmod
plat.build Top! do_program: ("--flash" in sys.argv)