Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-04-19 23:12:11 +03:00
Code Issues Actions 6 Packages Projects Releases Wiki Activity

nes_apu.cpp: Added missing DPCM period table for PAL. (#9167)

Browse Source 
Fixes pitch being flat for DPCM sounds for nespal (and m82p). This is most apparent in Mr. Gimmick, though it affects all software that use the DPCM channel.
This commit is contained in:
0kmg 2022-01-18 17:23:12 -09:00 committed by GitHub
parent 0f1cd34f36
commit 412098b9e6
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 12 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/devices/sound/nes_apu.cpp
View File

@ -86,6 +86,7 @@ DEFINE_DEVICE_TYPE(NES_APU, nesapu_device, "nesapu", "N2A03 APU")
nesapu_device::nesapu_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, u32 clock)
: device_t(mconfig, type, tag, owner, clock)
, device_sound_interface(mconfig, *this)
, m_is_pal(0)
, m_samps_per_sync(0)
, m_buffer_size(0)
, m_stream(nullptr)
@ -121,6 +122,7 @@ void nesapu_device::device_reset()
void nesapu_device::device_clock_changed()
{
calculate_rates();
m_is_pal = m_clock == PAL_APU_CLOCK;
}
void nesapu_device::calculate_rates()
@ -207,8 +209,8 @@ void nesapu_device::device_start()
save_item(NAME(m_APU.tail));
#else
save_item(NAME(m_APU.buf_pos));
save_item(NAME(m_APU.step_mode));
#endif
save_item(NAME(m_APU.step_mode));
}
/* TODO: sound channels should *ALL* have DC volume decay */
@ -433,7 +435,7 @@ s8 nesapu_device::apu_dpcm(apu_t::dpcm_t *chan)
if (chan->enabled)
{
freq = dpcm_clocks[chan->regs[0] & 0x0F];
freq = dpcm_clocks[m_is_pal][chan->regs[0] & 0x0F];
chan->phaseacc -= 4;
while (chan->phaseacc < 0)

3
src/devices/sound/nes_apu.h
View File

@ -68,9 +68,12 @@ private:
/* GLOBAL CONSTANTS */
static constexpr unsigned SYNCS_MAX1 = 0x20;
static constexpr unsigned SYNCS_MAX2 = 0x80;
static constexpr u32 NTSC_APU_CLOCK = 21477272 / 12;
static constexpr u32 PAL_APU_CLOCK = 26601712 / 16;
// internal state
apu_t m_APU; /* Actual APUs */
int m_is_pal;
u32 m_samps_per_sync; /* Number of samples per vsync */
u32 m_buffer_size; /* Actual buffer size in bytes */
u32 m_vbl_times[0x20]; /* VBL durations in samples */

8
src/devices/sound/nes_defs.h
View File

@ -211,10 +211,12 @@ static const int noise_freq[16] =
4, 8, 16, 32, 64, 96, 128, 160, 202, 254, 380, 508, 762, 1016, 2034, 2046
};
/* dpcm transfer freqs */
static const int dpcm_clocks[16] =
// dpcm (cpu) cycle period
// each frequency is determined as: freq = master / period
static const int dpcm_clocks[2][16] =
{
428, 380, 340, 320, 286, 254, 226, 214, 190, 160, 142, 128, 106, 85, 72, 54
{ 428, 380, 340, 320, 286, 254, 226, 214, 190, 160, 142, 128, 106, 85, 72, 54 }, // NTSC
{ 398, 354, 316, 298, 276, 236, 210, 198, 176, 148, 132, 118, 98, 78, 66, 50 } // PAL
};
/* ratios of pos/neg pulse for square waves */