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author | Vas Crabb <vas@vastheman.com> | 2018-07-07 02:40:29 +1000 |
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committer | Vas Crabb <vas@vastheman.com> | 2018-07-07 02:40:29 +1000 |
commit | c3fb11c2c98a5c28ece6a27093a0f9def350ac64 (patch) | |
tree | c68b38f05ed1d32358add721fda7f45e8803479f /src/mame/drivers/tranz330.cpp | |
parent | 5d9e33b786d7ef452317439359f3cbd8cc920513 (diff) |
devcb3
There are multiple issues with the current device callbacks:
* They always dispatch through a pointer-to-member
* Chained callbacks are a linked list so the branch unit can't predict the early
* There's a runtime decision made on the left/right shift direction
* There are runtime NULL checks on various objects
* Binding a lambda isn't practical
* Arbitrary transformations are not supported
* When chaining callbacks it isn't clear what the MCFG_DEVCB_ modifiers apply to
* It isn't possible to just append to a callback in derived configuration
* The macros need a magic, hidden local called devcb
* Moving code that uses the magic locals around is error-prone
* Writing the MCFG_ macros to make a device usable is a pain
* You can't discover applicable MCFG_ macros with intellisense
* Macros are not scoped
* Using an inappropriate macro isn't detected at compile time
* Lots of other things
This changeset overcomes the biggest obstacle to remving MCFG_ macros
altogether. Essentially, to allow a devcb to be configured, call
.bind() and expose the result (a bind target for the callback). Bind
target methods starting with "set" repace the current callbacks; methods
starting with "append" append to them. You can't reconfigure a callback
after resolving it. There's no need to use a macro matching the
handler signatures - use FUNC for everything. Current device is implied
if no tag/finder is supplied (no need for explicit this).
Lambdas are supported, and the memory space and offset are optional.
These kinds of things work:
* .read_cb().set([this] () { return something; });
* .read_cb().set([this] (offs_t offset) { return ~offset; });
* .write_cb().set([this] (offs_t offset, u8 data) { m_array[offset] = data; });
* .write_cb().set([this] (int state) { some_var = state; });
Arbitrary transforms are allowed, and they can modify offset/mask for example:
* .read_cb().set(FUNC(my_state::handler)).transform([] (u8 data) { return bitswap<4>(data, 1, 3, 0, 2); });
* .read_cb().set(m_dev, FUNC(some_device::member)).transform([] (offs_t &offset, u8 data) { offset ^= 3; return data; });
It's possible to stack arbitrary transforms, at the cost of compile
time (the whole transform stack gets inlined at compile time). Shifts
count as an arbitrary transform, but mask/exor does not.
Order of mask/shift/exor now matters. Modifications are applied in the
specified order. These are NOT EQUIVALENT:
* .read_cb().set(FUNC(my_state::handler)).mask(0x06).lshift(2);
* .read_cb().set(FUNC(my_state::handler)).lshift(2).mask(0x06);
The bit helper no longer reverses its behaviour for read callbacks, and
I/O ports are no longer aware of the field mask. Binding a read
callback to no-op is not supported - specify a constant. The GND and
VCC aliases have been removed intentionally - they're TTL-centric, and
were already being abused.
Other quirks have been preserved, including write logger only logging
when the data is non-zero (quite unhelpful in many of the cases where
it's used). Legacy syntax is still supported for simple cases, but will
be phased out. New devices should not have MCFG_ macros.
I don't think I've missed any fundamental issues, but if I've broken
something, let me know.
Diffstat (limited to 'src/mame/drivers/tranz330.cpp')
-rw-r--r-- | src/mame/drivers/tranz330.cpp | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/src/mame/drivers/tranz330.cpp b/src/mame/drivers/tranz330.cpp index 147a626abf0..f81be4882b1 100644 --- a/src/mame/drivers/tranz330.cpp +++ b/src/mame/drivers/tranz330.cpp @@ -148,12 +148,12 @@ void tranz330_state::tranz330(machine_config &config) m_cpu->set_daisy_config(tranz330_daisy_chain); CLOCK(config, "ctc_clock", XTAL(7'159'090)/4) // ? - .set_signal_handler(DEVCB_WRITELINE(*this, tranz330_state, clock_w)); + .signal_handler().set(FUNC(tranz330_state::clock_w)); MSM6242(config, RTC_TAG, XTAL(32'768)); - INPUT_MERGER_ANY_HIGH(config, "irq", 0) - .set_output_handler(DEVCB_INPUTLINE(m_cpu, INPUT_LINE_IRQ0)); + INPUT_MERGER_ANY_HIGH(config, "irq") + .output_handler().set_inputline(m_cpu, INPUT_LINE_IRQ0); Z80PIO(config, m_pio, XTAL(7'159'090)/2); //* m_pio->set_out_int_callback(DEVCB_WRITELINE("irq", input_merger_device, in_w<0>)); //* @@ -173,9 +173,9 @@ void tranz330_state::tranz330(machine_config &config) m_ctc->set_intr_callback(DEVCB_WRITELINE("irq", input_merger_device, in_w<2>)); RS232_PORT(config, m_rs232, default_rs232_devices, nullptr); - m_rs232->set_rxd_handler(DEVCB_WRITELINE(m_dart, z80dart_device, rxb_w)); - m_rs232->set_dcd_handler(DEVCB_WRITELINE(m_dart, z80dart_device, dcdb_w)); - m_rs232->set_cts_handler(DEVCB_WRITELINE(m_dart, z80dart_device, ctsb_w)); + m_rs232->rxd_handler().set(m_dart, FUNC(z80dart_device::rxb_w)); + m_rs232->dcd_handler().set(m_dart, FUNC(z80dart_device::dcdb_w)); + m_rs232->cts_handler().set(m_dart, FUNC(z80dart_device::ctsb_w)); // video MIC10937(config, VFD_TAG).set_port_value(0); |