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dp8344: Unconditional RET only takes 2 T-states (nw)

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This commit is contained in:
AJR 2019-12-01 17:24:26 -05:00
parent dc03095a7d
commit f06282380a
2 changed files with 10 additions and 4 deletions
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12
src/devices/cpu/bcp/dp8344.cpp
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@ -1494,8 +1494,14 @@ dp8344_device::inst_state dp8344_device::decode_instruction()
else if ((m_latched_instr & 0xff00) == 0xaf00)
{
// RET or RETF
if (BIT(m_latched_instr, 7) || get_flag(m_latched_instr & 0x0007) == BIT(m_latched_instr, 3))
return TX_RET;
if (BIT(m_latched_instr, 7))
{
address_stack_pop((m_latched_instr & 0x0060) >> 5, BIT(m_latched_instr, 4));
instruction_wait();
return T2_NEXT;
}
else if (get_flag(m_latched_instr & 0x0007) == BIT(m_latched_instr, 3))
return TX_RETF;
else
{
instruction_wait();
@ -1832,7 +1838,7 @@ void dp8344_device::execute_run()
m_inst_state = T2_NEXT;
break;
case TX_RET:
case TX_RETF:
address_stack_pop((m_latched_instr & 0x0060) >> 5, BIT(m_latched_instr, 4));
instruction_wait();
m_inst_state = T2_NEXT;

2
src/devices/cpu/bcp/dp8344.h
View File

@ -89,7 +89,7 @@ private:
enum inst_state : u8 {
T1_DECODE, T1_START, T1_SKIP, T1_LJMP, T1_LCALL,
TX_READ, TX_WRITE,
TX1_JRMK, TX1_JMP, TX2_JMP, TX_CALL, TX_RET,
TX1_JRMK, TX1_JMP, TX2_JMP, TX_CALL, TX_RETF,
T2_NEXT, T2_STORE, T2_READ, T2_WRITE, T2_ABSOLUTE
};