Understanding PLLs - Maverick-Shark/retroGuru GitHub Wiki

MiST

• Cyclone III
• 25K
• EP3C25E144C8
• 27 MHz

SiDi

• Cyclone III
• 22K
• EP5C22F14
• 27 MHz

NeptUNO/UA2

• Cyclone IV
• 55K
• EP4CE55
• 20 MHz

Poseidon CGX150

• Cyclone IV
• 150K
• EP4CGX150
• 50 MHz

zx48

• ZX Spectrum main processor runs at 3.54690 MHz, as opposed to 3.50000 MHz.

* MiST (27 MHz)
clk0 - 27,50,56
clk1 - 27,50,56 (-4464,-90º)

* SiDi
clk0 - 27,50,56

* NeptUNO (50 MHz)
pll0(clk0) - 25,50,28
pll1(clk1) - 50000000,50,56750401

* Poseidon
clk0 - 25,50,28
clk0 - 25,50,28 (-4464, -90º)

• ZX Spectrum main processor runs at 3.54690 MHz, as opposed to 3.50000 MHz.

3.5     x 16 = 56
3.54690 x 16 = 56750401

* MiST (27 MHz)
27 Mhz
------ x 56 = 56
  27

* NeptUNO (50 MHz)
50 Mhz
------ x 28 = 2 x 28 = 56
  25

From:

• Kyp069 ZX48
• Kyp069 ZX
• Kyp069 ZX128

Elan Enterprise (Zilog Z80A 4Mhz)

* MiSTer (50 MHz)
pll32 clk0 - 32
      clk1 - 64
      clk2 - 64
pll56 clk0 - 56,944444

* NeptUNO
pll32 clk0 - 25,50,16
      clk1 - 25,50,32
pll56 clk0 - 25000000,50,28475073

* Poseidon
pll32 clk0 - 25,50,16
pll56 clk0 - 25000000,50,28475073

From:

• Kyp069 EP