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pipistrello: run at 83+1/3 MHz, cleanup CRG

This commit is contained in:
Robert Jordens 2015-06-22 18:48:31 -06:00
parent 01c5051866
commit 2150e6cfef
1 changed files with 12 additions and 10 deletions
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22
targets/pipistrello.py
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@ -20,7 +20,13 @@ class _CRG(Module):
self.clk4x_wr_strb = Signal()
self.clk4x_rd_strb = Signal()
f0 = 50*1000000
f0 = Fraction(50, 1)*1000000
p = 12
f = Fraction(clk_freq*p, f0)
n, d = f.numerator, f.denominator
assert 19e6 <= f0/d <= 500e6 # pfd
assert 400e6 <= f0*n/d <= 1080e6 # vco
clk50 = platform.request("clk50")
clk50a = Signal()
self.specials += Instance("IBUFG", i_I=clk50, o_O=clk50a)
@ -28,10 +34,6 @@ class _CRG(Module):
self.specials += Instance("BUFIO2", p_DIVIDE=1,
p_DIVIDE_BYPASS="TRUE", p_I_INVERT="FALSE",
i_I=clk50a, o_DIVCLK=clk50b)
f = Fraction(int(clk_freq), int(f0))
n, m = f.denominator, f.numerator
assert f0/n*m == clk_freq
p = 8
pll_lckd = Signal()
pll_fb = Signal()
pll = Signal(6)
@ -39,9 +41,9 @@ class _CRG(Module):
p_BANDWIDTH="OPTIMIZED", p_COMPENSATION="INTERNAL",
p_REF_JITTER=.01, p_CLK_FEEDBACK="CLKFBOUT",
i_DADDR=0, i_DCLK=0, i_DEN=0, i_DI=0, i_DWE=0, i_RST=0, i_REL=0,
p_DIVCLK_DIVIDE=1, p_CLKFBOUT_MULT=m*p//n, p_CLKFBOUT_PHASE=0.,
p_DIVCLK_DIVIDE=d, p_CLKFBOUT_MULT=n, p_CLKFBOUT_PHASE=0.,
i_CLKIN1=clk50b, i_CLKIN2=0, i_CLKINSEL=1,
p_CLKIN1_PERIOD=1000000000/f0, p_CLKIN2_PERIOD=0.,
p_CLKIN1_PERIOD=1e9/f0, p_CLKIN2_PERIOD=0.,
i_CLKFBIN=pll_fb, o_CLKFBOUT=pll_fb, o_LOCKED=pll_lckd,
o_CLKOUT0=pll[0], p_CLKOUT0_DUTY_CYCLE=.5,
o_CLKOUT1=pll[1], p_CLKOUT1_DUTY_CYCLE=.5,
@ -50,7 +52,7 @@ class _CRG(Module):
o_CLKOUT4=pll[4], p_CLKOUT4_DUTY_CYCLE=.5,
o_CLKOUT5=pll[5], p_CLKOUT5_DUTY_CYCLE=.5,
p_CLKOUT0_PHASE=0., p_CLKOUT0_DIVIDE=p//4, # sdram wr rd
p_CLKOUT1_PHASE=0., p_CLKOUT1_DIVIDE=p//8,
p_CLKOUT1_PHASE=0., p_CLKOUT1_DIVIDE=p//4,
p_CLKOUT2_PHASE=270., p_CLKOUT2_DIVIDE=p//2, # sdram dqs adr ctrl
p_CLKOUT3_PHASE=250., p_CLKOUT3_DIVIDE=p//2, # off-chip ddr
p_CLKOUT4_PHASE=0., p_CLKOUT4_DIVIDE=p//1,
@ -96,8 +98,8 @@ class BaseSoC(SDRAMSoC):
}
csr_map.update(SDRAMSoC.csr_map)
def __init__(self, platform, sdram_controller_settings=LASMIconSettings(), **kwargs):
clk_freq = 75*1000000
def __init__(self, platform, sdram_controller_settings=LASMIconSettings(),
clk_freq=(83 + Fraction(1, 3))*1000*1000, **kwargs):
SDRAMSoC.__init__(self, platform, clk_freq,
cpu_reset_address=0x170000, # 1.5 MB
sdram_controller_settings=sdram_controller_settings,