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[garyopa]

Here is the Corona source code:

CODE

– Xbox 360 slim reset glitch hack, 48Mhz clock + fake POST + i2c version
– by GliGli – Corona Added by Team Xecuter

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.ALL;

entity main is
generic (
SCL_BITS : STD_LOGIC_VECTOR(255 downto 0) := b"1100100100100100100100100100001111100001001001001001001001001000011111000010010010010010010010010000111110000100100100100100100100100001111100001001001001001001001001000011111000010010010010010010010010000111110000100100100100100100100100001111100001111111";
SDA_SLOW_BITS : STD_LOGIC_VECTOR(255 downto 0) := b"1001111111110000000000000001111111111111111100000011111111111111111111111000000000000000111000000111111111110000001111110000000000001111111111100011100011100011100000011111111111000111000111000111000000111111111110000000000001110000000001111111111100101111";
SDA_FAST_BITS : STD_LOGIC_VECTOR(255 downto 0) := b"1001111111110000000000000001111111111111111100000011111111111111111111111000000000000000111000000111111111111111110000000000000000001111111111111100011100011111100000011111111111000111000000000111000000111111111110001110000000000000000001111111111100101111"
);
port (
DBG : out STD_LOGIC := '0';
POSTBIT : in STD_LOGIC;
CLK : in STD_LOGIC;
CPU_RESET : inout STD_LOGIC := 'Z';
SDA : out  STD_LOGIC := 'Z';
SCL : out  STD_LOGIC := 'Z'
);
end main;

architecture counter of main is

constant I2C_CNT_WIDTH : integer := 15;
constant I2C_CLK_DIV : integer := 128;

constant CNT_WIDTH : integer := 16;
constant POSTCNT_WIDTH : integer := 4;

constant POST_B8 : integer := 10;
constant POST_BA : integer := 11;
constant POST_BB : integer := 12;

constant WIDTH_RESET_START  : integer := 21864; –17357; — 8678 — corona 21863 +1
constant WIDTH_RESET_END: integer := 3; –2; — 1 — corona 2 no cap 3 with 220/270pf cap

constant TIME_RESET_START  : integer := WIDTH_RESET_START;
constant TIME_RESET_END: integer := TIME_RESET_START+WIDTH_RESET_END;
constant TIME_BYPASS_END   : integer := 65535;

signal i2ccnt : integer range 0 to 2**I2C_CNT_WIDTH-1 := 2**I2C_CNT_WIDTH-1;
signal pslo : STD_LOGIC := '0';
signal slo : STD_LOGIC := '0';

signal cnt : integer range 0 to 2**CNT_WIDTH-1 := 0;
signal postcnt : integer range 0 to 2**POSTCNT_WIDTH-1 := 0;
signal pp: STD_LOGIC := '0';
signal ppp: STD_LOGIC := '0';
signal rst: STD_LOGIC := '0';

begin
process(CLK, POSTBIT, CPU_RESET, postcnt, rst) is
begin
if CLK'event then
–if rising_edge(CLK) then
– fake POST
if (cnt = 0) and (CPU_RESET = '0') then
postcnt <= 0;
pp <= '0';
ppp <= '0';
else
if ((postcnt = POST_B8) or (POSTBIT = ppp)) and ((POSTBIT xor pp) = '1') then — detect POST changes / filter POST / don't filter glitch POST
if postcnt<2**POSTCNT_WIDTH-1 then
postcnt <= postcnt + 1;
end if;
pp <= POSTBIT;
else
ppp <= POSTBIT;
end if;
end if;

– main counter
if (postcnt < POST_BA) or (postcnt > POST_BB) then
cnt <= 0;
else
if cnt<2**CNT_WIDTH-1 then
cnt <= cnt + 1;
end if;
end if;

– slow flag
if (postcnt >= POST_B8)  and (postcnt <= POST_BB) and (cnt < TIME_BYPASS_END) then
slo <= '1';
else
slo <= '0';
end if;

– reset
if (cnt >= TIME_RESET_START) and (cnt < TIME_RESET_END) then
rst <= '0';
else
rst <= '1';
end if;
end if;

if rst = '0' then
CPU_RESET <= '0';
else
CPU_RESET <= 'Z';
end if;

DBG <= slo;
end process;

– i2c commands streamer
process(CLK, slo, cnt) is
begin
if rising_edge(CLK) then
if i2ccnt / I2C_CLK_DIV /= 255 then
i2ccnt <= i2ccnt + 1;
pslo <= slo;
else
if pslo /= slo then
i2ccnt <= 0;
end if;
end if;
end if;

if ((slo = '1') and (SDA_SLOW_BITS(255 – i2ccnt / I2C_CLK_DIV) = '1')) or ((slo = '0') and (SDA_FAST_BITS(255 – i2ccnt / I2C_CLK_DIV) = '1')) then
SDA <= 'Z';
else
SDA <= '0';
end if;

if SCL_BITS(255 – i2ccnt / I2C_CLK_DIV) = '1' then
SCL <= 'Z';
else
SCL <= '0';
end if;

end process;

end counter;

More info at the official T-X site linked above in the first news post!