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authorGravatarGravatar couriersud <couriersud@gmx.org>2020-02-17 22:11:35 +0100
committerGravatarGravatar couriersud <couriersud@gmx.org>2020-02-17 22:11:35 +0100
commit10ee67428236b8dd58e13d4e7b9652190eeba332 (patch) (github)
treeda595630a4c56cfd84827a4f012c58a24b2598f7
parentfbd9055a904e569da4c7bfe3360712af74b1fc5d (diff)
downloadmame-10ee67428236b8dd58e13d4e7b9652190eeba332.tar.bz2
mame-10ee67428236b8dd58e13d4e7b9652190eeba332.zip
netlist: change output impedance to more realistic values. (nw)
-rw-r--r--src/lib/netlist/nl_base.cpp7
1 files changed, 5 insertions, 2 deletions
diff --git a/src/lib/netlist/nl_base.cpp b/src/lib/netlist/nl_base.cpp
index 336f6783e8f..36f0e6df31f 100644
--- a/src/lib/netlist/nl_base.cpp
+++ b/src/lib/netlist/nl_base.cpp
@@ -66,8 +66,10 @@ namespace netlist
// m_low_V - these depend on sinked/sourced current. Values should be suitable for typical applications.
m_low_VO = nlconst::magic(0.05);
m_high_VO = nlconst::magic(0.05); // 4.95
- m_R_low = nlconst::magic(10.0);
- m_R_high = nlconst::magic(10.0);
+ // https://www.classe.cornell.edu/~ib38/teaching/p360/lectures/wk09/l26/EE2301Exp3F10.pdf
+ // typical CMOS may sink 0.4mA while output stays <= 0.4V
+ m_R_low = nlconst::magic(500.0);
+ m_R_high = nlconst::magic(500.0);
}
unique_pool_ptr<devices::nld_base_d_to_a_proxy> create_d_a_proxy(netlist_state_t &anetlist, const pstring &name, logic_output_t *proxied) const override;
unique_pool_ptr<devices::nld_base_a_to_d_proxy> create_a_d_proxy(netlist_state_t &anetlist, const pstring &name, logic_input_t *proxied) const override;
@@ -559,6 +561,7 @@ namespace netlist
, m_active_outputs(*this, "m_active_outputs", 1)
{
set_logic_family(owner.logic_family());
+ //printf("%s %f %f\n", this->name().c_str(), logic_family()->R_low(), logic_family()->R_high());
if (logic_family() == nullptr)
set_logic_family(family_TTL());
owner.state().register_device(this->name(), owned_pool_ptr<core_device_t>(this, false));