URL
https://opencores.org/ocsvn/cpu_lecture/cpu_lecture/trunk
Subversion Repositories cpu_lecture
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- This comparison shows the changes necessary to convert path
/
- from Rev 12 to Rev 13
- ↔ Reverse comparison
Rev 12 → Rev 13
/cpu_lecture/trunk/src/opc_deco.vhd
290,8 → 290,12
else Q_AMOD <= AMOD_Yq; |
end if; |
|
Q_RD_M <= not I_OPC(9); -- '1' if LDD |
Q_WE_M <= '0' & I_OPC(9); -- "01" if STD |
if (I_OPC(9) = '0') then -- LDD |
Q_RD_M <= I_T0 ; |
Q_WE_D <= '0' & not I_T0; |
else -- STD |
Q_WE_M <= '0' & I_OPC(9); |
end if; |
|
when "100100" => -- 1001 00xx xxxx xxxx |
Q_IMM <= I_OPC(31 downto 16); -- absolute address for LDS/STS |
/cpu_lecture/trunk/src/opc_fetch.vhd
113,6 → 113,8
|
-- Two cycle opcodes: |
-- |
-- 10q0 qq0d dddd 1qqq - LDD (Y + q) |
-- 10q0 qq0d dddd 0qqq - LDD (Z + q) |
-- 1001 000d dddd .... - LDS etc. |
-- 1001 0101 0000 1000 - RET |
-- 1001 0101 0001 1000 - RETI |
122,12 → 124,15
-- 1111 111r rrrr 0bbb - SBRS |
-- |
L_WAIT <= '0' when ((L_INVALIDATE = '1') or (I_INTVEC(5) = '1')) |
else L_T0 when ((P_OPC(15 downto 9) = "1001000" ) -- LDS etc. |
or ((P_OPC(15 downto 8) = "10010101") -- RET etc. |
and (P_OPC(3 downto 0) /= "1010")) -- but not DEC |
or ((P_OPC(15 downto 10) = "100110") -- SBIC, SBIS |
and (P_OPC(8) = '1')) |
or (P_OPC(15 downto 10) = "111111")) -- SBRC, SBRS |
else L_T0 when ( ( (P_OPC(15 downto 14) = "10" ) -- LDD |
and (P_OPC(12) = '0') |
and (P_OPC( 9) = '0') ) |
or ( P_OPC(15 downto 9) = "1001000") -- LDS etc. |
or ( ( P_OPC(15 downto 8) = "10010101") -- RET etc. |
and (P_OPC( 3 downto 0) /= "1010")) -- but not DEC |
or ( ( P_OPC(15 downto 10) = "100110") -- SBI[CS] |
and (P_OPC(8) = '1')) |
or (P_OPC(15 downto 10) = "111111")) -- SBR[CS] |
else '0'; |
|
L_INVALIDATE <= I_CLR or I_SKIP; |