From 237e8e235f5a61ce9375ced26616dad6da3b8943 Mon Sep 17 00:00:00 2001 From: "R. Belmont" Date: Mon, 12 Aug 2013 03:54:45 +0000 Subject: [PATCH] MC6801/6803 updates: [R. Belmont] * Support for timer output capture to pin P21 * Support for externally-clocked serial * Added devcb2 hook for serial xmit to easily differentiate xmit from other Port 2 updates. Bits are still also sent to Port 2 of course. --- src/emu/cpu/m6800/m6800.c | 45 +++++++++++++++++++++++++++++++++------ src/emu/cpu/m6800/m6800.h | 10 +++++++-- 2 files changed, 46 insertions(+), 9 deletions(-) diff --git a/src/emu/cpu/m6800/m6800.c b/src/emu/cpu/m6800/m6800.c index ee9f64ff7c6..825bb225e04 100644 --- a/src/emu/cpu/m6800/m6800.c +++ b/src/emu/cpu/m6800/m6800.c @@ -536,6 +536,7 @@ m6800_cpu_device::m6800_cpu_device(const machine_config &mconfig, const char *ta , m_io_config("io", ENDIANNESS_BIG, 8, 9, 0) , m_has_io(false) , m_out_sc2_func(*this) + , m_out_sertx_func(*this) , m_insn(m6800_insn) , m_cycles(cycles_6800) { @@ -548,6 +549,7 @@ m6800_cpu_device::m6800_cpu_device(const machine_config &mconfig, device_type ty , m_io_config("io", ENDIANNESS_BIG, 8, 9, 0) , m_has_io(has_io) , m_out_sc2_func(*this) + , m_out_sertx_func(*this) , m_insn(insn) , m_cycles(cycles) { @@ -730,6 +732,15 @@ void m6800_cpu_device::check_timer_event() m_wai_state &= ~M6800_SLP; if ( !(CC & 0x10) && (m_tcsr & TCSR_EOCI)) TAKE_OCI; + + // if output on P21 is enabled, let's do it + if (m_port2_ddr & 2) + { + m_port2_data &= ~2; + m_port2_data |= (m_tcsr & TCSR_OLVL) << 1; + m_port2_written = 1; + write_port2(); + } } /* TOI */ if( CTD >= TOD) @@ -767,7 +778,12 @@ void m6800_cpu_device::set_rmcr(UINT8 data) switch ((m_rmcr & M6800_RMCR_CC_MASK) >> 2) { case 0: - case 3: // not implemented + m_sci_timer->enable(false); + m_use_ext_serclock = false; + break; + + case 3: // external clock + m_use_ext_serclock = true; m_sci_timer->enable(false); break; @@ -778,6 +794,7 @@ void m6800_cpu_device::set_rmcr(UINT8 data) int clock = m_clock / m_clock_divider; m_sci_timer->adjust(attotime::from_hz(clock / divisor), 0, attotime::from_hz(clock / divisor)); + m_use_ext_serclock = false; } break; } @@ -844,8 +861,8 @@ void m6800_cpu_device::serial_transmit() case M6800_SERIAL_START: if (m_trcsr & M6800_TRCSR_TDRE) { - // transmit buffer is empty, send consecutive '1's - m_tx = 1; + // transmit buffer is empty, send nothing + return; } else { @@ -892,6 +909,7 @@ void m6800_cpu_device::serial_transmit() break; } + m_out_sertx_func((m_tx == 1) ? ASSERT_LINE : CLEAR_LINE); m_port2_written = 1; write_port2(); } @@ -1023,6 +1041,7 @@ void m6800_cpu_device::device_start() m_io = &space(AS_IO); m_out_sc2_func.resolve_safe(); + m_out_sertx_func.resolve_safe(); m_sci_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(m6800_cpu_device::sci_tick),this)); save_item(NAME(m_ppc.w.l)); @@ -1144,6 +1163,8 @@ void m6800_cpu_device::device_reset() m_trcsr_read_tdre = 0; m_trcsr_read_orfe = 0; m_trcsr_read_rdrf = 0; + m_ext_serclock = 0; + m_use_ext_serclock = false; set_rmcr(0); } @@ -1479,9 +1500,6 @@ WRITE8_MEMBER( m6800_cpu_device::m6801_io_w ) { m_port2_ddr = data; write_port2(); - - if (m_port2_ddr & 2) - logerror("CPU '%s' PC %04x: warning - port 2 bit 1 set as output (OLVL) - not supported\n",space.device().tag(),space.device().safe_pc()); } break; @@ -1683,6 +1701,20 @@ WRITE8_MEMBER( m6800_cpu_device::m6801_io_w ) } } +void m6801_cpu_device::m6801_clock_serial() +{ + if (m_use_ext_serclock) + { + m_ext_serclock++; + + if (m_ext_serclock >= 8) + { + m_ext_serclock = 0; + serial_transmit(); + serial_receive(); + } + } +} offs_t m6800_cpu_device::disasm_disassemble(char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram, UINT32 options) { @@ -1739,4 +1771,3 @@ offs_t nsc8105_cpu_device::disasm_disassemble(char *buffer, offs_t pc, const UIN return CPU_DISASSEMBLE_NAME(nsc8105)(this, buffer, pc, oprom, opram, options); } - diff --git a/src/emu/cpu/m6800/m6800.h b/src/emu/cpu/m6800/m6800.h index e92d4ece9c9..6560f738e99 100644 --- a/src/emu/cpu/m6800/m6800.h +++ b/src/emu/cpu/m6800/m6800.h @@ -46,7 +46,8 @@ enum #define MCFG_M6801_SC2(_devcb) \ m6800_cpu_device::set_out_sc2_func(*device, DEVCB2_##_devcb); - +#define MCFG_M6801_SER_TX(_devcb) \ + m6800_cpu_device::set_out_sertx_func(*device, DEVCB2_##_devcb); class m6800_cpu_device : public cpu_device { @@ -59,6 +60,7 @@ public: // static configuration helpers template static devcb2_base &set_out_sc2_func(device_t &device, _Object object) { return downcast(device).m_out_sc2_func.set_callback(object); } + template static devcb2_base &set_out_sertx_func(device_t &device, _Object object) { return downcast(device).m_out_sertx_func.set_callback(object); } DECLARE_READ8_MEMBER( m6801_io_r ); DECLARE_WRITE8_MEMBER( m6801_io_w ); @@ -92,6 +94,7 @@ protected: bool m_has_io; devcb2_write_line m_out_sc2_func; + devcb2_write_line m_out_sertx_func; PAIR m_ppc; /* Previous program counter */ PAIR m_pc; /* Program counter */ @@ -135,7 +138,8 @@ protected: int m_clock_divider; UINT8 m_trcsr, m_rmcr, m_rdr, m_tdr, m_rsr, m_tsr; - int m_rxbits, m_txbits, m_txstate, m_trcsr_read_tdre, m_trcsr_read_orfe, m_trcsr_read_rdrf, m_tx; + int m_rxbits, m_txbits, m_txstate, m_trcsr_read_tdre, m_trcsr_read_orfe, m_trcsr_read_rdrf, m_tx, m_ext_serclock; + bool m_use_ext_serclock; int m_port2_written; int m_icount; @@ -425,6 +429,8 @@ public: m6801_cpu_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock); m6801_cpu_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source, const m6800_cpu_device::op_func *insn, const UINT8 *cycles, address_map_constructor internal = NULL); + void m6801_clock_serial(); + protected: virtual UINT64 execute_clocks_to_cycles(UINT64 clocks) const { return (clocks + 4 - 1) / 4; } virtual UINT64 execute_cycles_to_clocks(UINT64 cycles) const { return (cycles * 4); }