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Diffstat (limited to 'trunk/src/emu/machine/mb87078.c')
-rw-r--r-- | trunk/src/emu/machine/mb87078.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/trunk/src/emu/machine/mb87078.c b/trunk/src/emu/machine/mb87078.c new file mode 100644 index 00000000000..26cd8680ac0 --- /dev/null +++ b/trunk/src/emu/machine/mb87078.c @@ -0,0 +1,278 @@ +/***************************************************************************** + + Fujitsu MB87078 6-bit, 4-channel electronic volume controller emulator + + An excerpt from the datasheet about the chip functionality: + "A digital signal input controls gain every 0.5 dB step from 0dB to -32dB. + - Gain variable range: 0 dB to -32 dB by 0.5dB or -infinity + - Gain variable range is expanded to connect two channels serially (0 dB to -64 dB) + - Each channel gain can be set respectively + - Test function is provided (to confirm internal data) + - Data is initialized by reset signal (all channels are set to 0dB) + - Logic I/O is TTL comatible" + + There are 6 digital data input/output pins and DSEL pin that selects + the group (there are two) of internal registers to be read/written. + + Group 0 is 6-bit gain latch + Group 1 is 5-bit control latch (2-bits are channel select and 3-bits are volume control) + + Digital I/O Setting: + /TC DSEL D0 D1 D2 D3 D4 D5 I/O MODES (when /TC==H ->write) + H H DSC1 DSC2 EN C0 C32 X Input mode + H L GD0 GD1 GD2 GD3 GD4 GD5 (set) + L H DSC1 DSC2 EN C0 C32 L Output mode + L L GD0 GD1 GD2 GD3 GD4 GD5 (check) + + Channel Setting: + DSC2 DSC1 CHANNEL + L L 0 + L H 1 + H L 2 + H H 3 + + Electrical Volume Setting: + DATA* GAIN + GD5 GD4 GD3 GD2 GD1 GD0 EN C0 C32 (dB) + 1 1 1 1 1 1 1 0 0 0 + 1 1 1 1 1 0 1 0 0 -0.5 + 1 1 1 1 0 1 1 0 0 -1 + 1 1 1 1 0 0 1 0 0 -1.5 + 1 1 1 0 1 1 1 0 0 -2 + [..........................................] + 0 0 0 0 0 1 1 0 0 -31 + 0 0 0 0 0 0 1 0 0 -31.5 + X X X X X X 1 X 1 -32 + X X X X X X 1 1 0 0 + X X X X X X 0 X X -infinity + + X=don't care + * When reset, DATA is set to 0 dB (code 111111 100) + + + MB87078 pins and assigned interface variables/functions + + /[ 1] D0 /TC [24] + | [ 2] D1 /WR [23] + MB87078_data_w()| [ 3] D2 /CE [22] + MB87078_data_r()| [ 4] D3 DSEL [21]-MB87078_data_w()/data_r() parameter + | [ 5] D4 /RESET [20]-MB87078_reset_comp_w() + \[ 6] D5 /PD [19] + [ 7] DGND VDD [18] + [ 8] AGND 1/2 VDD [17] + [ 9] AIN0 AOUT3 [16] + [10] AOUT0 AIN3 [15] + [11] AIN1 AOUT2 [14] + [12] AOUT1 AIN2 [13] + + + *****************************************************************************/ + +#include "emu.h" +#include "machine/mb87078.h" + +typedef struct _mb87078_state mb87078_state; +struct _mb87078_state +{ + int gain[4]; /* gain index 0-63,64,65 */ + int channel_latch; /* current channel */ + UINT8 latch[2][4]; /* 6bit+3bit 4 data latches */ + UINT8 reset_comp; + + mb87078_gain_changed_cb gain_changed_cb; +}; + + +static const float mb87078_gain_decibel[66] = { + 0.0, -0.5, -1.0, -1.5, -2.0, -2.5, -3.0, -3.5, + -4.0, -4.5, -5.0, -5.5, -6.0, -6.5, -7.0, -7.5, + -8.0, -8.5, -9.0, -9.5,-10.0,-10.5,-11.0,-11.5, + -12.0,-12.5,-13.0,-13.5,-14.0,-14.5,-15.0,-15.5, + -16.0,-16.5,-17.0,-17.5,-18.0,-18.5,-19.0,-19.5, + -20.0,-20.5,-21.0,-21.5,-22.0,-22.5,-23.0,-23.5, + -24.0,-24.5,-25.0,-25.5,-26.0,-26.5,-27.0,-27.5, + -28.0,-28.5,-29.0,-29.5,-30.0,-30.5,-31.0,-31.5, + -32.0, -256.0 + }; + +static const int mb87078_gain_percent[66] = { + 100,94,89,84,79,74,70,66, + 63,59,56,53,50,47,44,42, + 39,37,35,33,31,29,28,26, + 25,23,22,21,19,18,17,16, + 15,14,14,13,12,11,11,10, + 10, 9, 8, 8, 7, 7, 7, 6, + 6, 5, 5, 5, 5, 4, 4, 4, + 3, 3, 3, 3, 3, 2, 2, 2, + 2, 0 +}; + +/***************************************************************************** + INLINE FUNCTIONS +*****************************************************************************/ + +INLINE mb87078_state *get_safe_token( device_t *device ) +{ + assert(device != NULL); + assert(device->type() == MB87078); + + return (mb87078_state *)downcast<legacy_device_base *>(device)->token(); +} + +INLINE const mb87078_interface *get_interface( device_t *device ) +{ + assert(device != NULL); + assert((device->type() == MB87078)); + return (const mb87078_interface *) device->static_config(); +} + +/***************************************************************************** + IMPLEMENTATION +*****************************************************************************/ + +#define GAIN_MAX_INDEX 64 +#define GAIN_INFINITY_INDEX 65 + + +static int calc_gain_index( int data0, int data1 ) +{ +//data 0: GD0-GD5 +//data 1: 1 2 4 8 16 +// c1 c2 EN C0 C32 + + if (!(data1 & 0x04)) + { + return GAIN_INFINITY_INDEX; + } + else + { + if (data1 & 0x10) + { + return GAIN_MAX_INDEX; + } + else + { + if (data1 & 0x08) + { + return 0; + } + else + { + return (data0 ^ 0x3f); + } + } + } +} + + +static void gain_recalc( device_t *device ) +{ + mb87078_state *mb87078 = get_safe_token(device); + int i; + + for (i = 0; i < 4; i++) + { + int old_index = mb87078->gain[i]; + mb87078->gain[i] = calc_gain_index(mb87078->latch[0][i], mb87078->latch[1][i]); + if (old_index != mb87078->gain[i]) + mb87078->gain_changed_cb(device->machine(), i, mb87078_gain_percent[mb87078->gain[i]]); + } +} + + + +void mb87078_data_w( device_t *device, int data, int dsel ) +{ + mb87078_state *mb87078 = get_safe_token(device); + + if (mb87078->reset_comp == 0) + return; + + if (dsel == 0) /* gd0 - gd5 */ + { + mb87078->latch[0][mb87078->channel_latch] = data & 0x3f; + } + else /* dcs1, dsc2, en, c0, c32, X */ + { + mb87078->channel_latch = data & 3; + mb87078->latch[1][mb87078->channel_latch] = data & 0x1f; //always zero bit 5 + } + gain_recalc(device); +} + + +float mb87078_gain_decibel_r( device_t *device, int channel ) +{ + mb87078_state *mb87078 = get_safe_token(device); + return mb87078_gain_decibel[mb87078->gain[channel]]; +} + + +int mb87078_gain_percent_r( device_t *device, int channel ) +{ + mb87078_state *mb87078 = get_safe_token(device); + return mb87078_gain_percent[mb87078->gain[channel]]; +} + +void mb87078_reset_comp_w( device_t *device, int level ) +{ + mb87078_state *mb87078 = get_safe_token(device); + + mb87078->reset_comp = level; + + /*this seems to be true, according to the datasheets*/ + if (level == 0) + { + mb87078->latch[0][0] = 0x3f; + mb87078->latch[0][1] = 0x3f; + mb87078->latch[0][2] = 0x3f; + mb87078->latch[0][3] = 0x3f; + + mb87078->latch[1][0] = 0x0 | 0x4; + mb87078->latch[1][1] = 0x1 | 0x4; + mb87078->latch[1][2] = 0x2 | 0x4; + mb87078->latch[1][3] = 0x3 | 0x4; + } + + gain_recalc(device); +} + +/***************************************************************************** + DEVICE INTERFACE +*****************************************************************************/ + +static DEVICE_START( mb87078 ) +{ + mb87078_state *mb87078 = get_safe_token(device); + const mb87078_interface *intf = get_interface(device); + + mb87078->gain_changed_cb = intf->gain_changed_cb; + + device->save_item(NAME(mb87078->channel_latch)); + device->save_item(NAME(mb87078->reset_comp)); + device->save_item(NAME(mb87078->latch[0])); + device->save_item(NAME(mb87078->latch[1])); + device->save_item(NAME(mb87078->gain)); +} + +static DEVICE_RESET( mb87078 ) +{ + mb87078_state *mb87078 = get_safe_token(device); + + mb87078->channel_latch = 0; + + /* reset chip */ + mb87078_reset_comp_w(device, 0); + mb87078_reset_comp_w(device, 1); +} + +static const char DEVTEMPLATE_SOURCE[] = __FILE__; + +#define DEVTEMPLATE_ID( p, s ) p##mb87078##s +#define DEVTEMPLATE_FEATURES DT_HAS_START | DT_HAS_RESET +#define DEVTEMPLATE_NAME "Fujitsu MB87078" +#define DEVTEMPLATE_FAMILY "Fujitsu Volume Controller MB87078" +#include "devtempl.h" + + +DEFINE_LEGACY_DEVICE(MB87078, mb87078); |