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Diffstat (limited to 'src/emu/machine/adc1213x.c')
-rw-r--r-- | src/emu/machine/adc1213x.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/src/emu/machine/adc1213x.c b/src/emu/machine/adc1213x.c new file mode 100644 index 00000000000..eef2493b03a --- /dev/null +++ b/src/emu/machine/adc1213x.c @@ -0,0 +1,251 @@ +/* + ADC12130/ADC12132/ADC12138 + + Self-calibrating 12-bit Plus Sign Serial I/O A/D Converters with MUX and Sample/Hold + + TODO: + - Only ADC12138 currently supported +*/ + +#include "driver.h" +#include "adc1213x.h" + +#define MAX_ADC1213X_CHIPS 4 + +typedef struct +{ + int cycle; + int data_out; + int data_in; + int conv_mode; + int auto_cal; + int auto_zero; + int acq_time; + int data_out_sign; + int mode; + int input_shift_reg; + int output_shift_reg; + int end_conv; + + double (*input_callback)(int input); +} ADC1213X; + +static ADC1213X adc1213x[MAX_ADC1213X_CHIPS]; + +#define ADC1213X_CONV_MODE_12_MSB_FIRST 0 +#define ADC1213X_CONV_MODE_16_MSB_FIRST 1 +#define ADC1213X_CONV_MODE_12_LSB_FIRST 2 +#define ADC1213X_CONV_MODE_16_LSB_FIRST 3 + +#define ADC1213X_ACQUISITION_TIME_6_CCLK 0 +#define ADC1213X_ACQUISITION_TIME_10_CCLK 1 +#define ADC1213X_ACQUISITION_TIME_18_CCLK 2 +#define ADC1213X_ACQUISITION_TIME_34_CCLK 3 + +int adc1213x_do_r(int chip) +{ + //printf("ADC: DO\n"); + return adc1213x[chip].data_out; +} + +void adc1213x_di_w(int chip, int state) +{ + adc1213x[chip].data_in = state & 1; +} + +static void adc1213x_convert(int chip, int channel, int bits16, int lsbfirst) +{ + int i; + int bits; + int input_value; + double input; + + if (bits16) + fatalerror("ADC1213X: 16-bit mode not supported\n"); + + if (lsbfirst) + fatalerror("ADC1213X: LSB first not supported\n"); + + switch (channel) + { + case 0x8: // H L L L - CH0 (single-ended) + { + input = adc1213x[chip].input_callback(0); + break; + } + case 0xc: // H H L L - CH1 (single-ended) + { + input = adc1213x[chip].input_callback(1); + break; + } + case 0x9: // H L L H - CH2 (single-ended) + { + input = adc1213x[chip].input_callback(2); + break; + } + case 0xd: // H H L H - CH3 (single-ended) + { + input = adc1213x[chip].input_callback(3); + break; + } + case 0xa: // H L H L - CH4 (single-ended) + { + input = adc1213x[chip].input_callback(4); + break; + } + case 0xe: // H H H L - CH5 (single-ended) + { + input = adc1213x[chip].input_callback(5); + break; + } + case 0xb: // H L H H - CH6 (single-ended) + { + input = adc1213x[chip].input_callback(6); + break; + } + case 0xf: // H H H H - CH7 (single-ended) + { + input = adc1213x[chip].input_callback(7); + break; + } + default: + { + fatalerror("ADC1213X: unsupported channel %02X\n", channel); + } + } + + input_value = (int)(input * 2047.0); + + bits = 12; + + // sign-extend if needed + if (adc1213x[chip].data_out_sign) + { + input_value = input_value | ((input_value & 0x800) << 1); + bits++; + } + + adc1213x[chip].output_shift_reg = 0; + + for (i=0; i < bits; i++) + { + if (input_value & (1 << ((bits-1) - i))) + { + adc1213x[chip].output_shift_reg |= (1 << i); + } + } + + adc1213x[chip].data_out = adc1213x[chip].output_shift_reg & 1; + adc1213x[chip].output_shift_reg >>= 1; +} + +void adc1213x_cs_w(int chip, int state) +{ + if (state) + { + //printf("ADC: CS\n"); + + if (adc1213x[chip].cycle >= 7) + { + int mode = adc1213x[chip].input_shift_reg >> (adc1213x[chip].cycle - 8); + + switch (mode & 0xf) + { + case 0x0: // X X X X L L L L - 12 or 13 Bit MSB First conversion + { + adc1213x_convert(chip, (mode >> 4) & 0xf, 0, 0); + break; + } + case 0x1: // X X X X L L L H - 16 or 17 Bit MSB First conversion + { + adc1213x_convert(chip, (mode >> 4) & 0xf, 1, 0); + break; + } + case 0x4: // X X X X L H L L - 12 or 13 Bit LSB First conversion + { + adc1213x_convert(chip, (mode >> 4) & 0xf, 0, 1); + break; + } + case 0x5: // X X X X L H L H - 16 or 17 Bit LSB First conversion + { + adc1213x_convert(chip, (mode >> 4) & 0xf, 1, 1); + break; + } + + default: + { + switch (mode) + { + case 0x08: // L L L L H L L L - Auto cal + { + adc1213x[chip].auto_cal = 1; + break; + } + + case 0x0e: // L L L L H H H L - Acquisition time 6 CCLK cycles + { + adc1213x[chip].acq_time = ADC1213X_ACQUISITION_TIME_6_CCLK; + break; + } + + case 0x8d: // H L L L H H L H - Data out with sign + { + adc1213x[chip].data_out_sign = 1; + break; + } + + default: + { + fatalerror("ADC1213X: unknown config mode %02X\n", mode); + } + } + break; + } + } + } + + adc1213x[chip].cycle = 0; + adc1213x[chip].input_shift_reg = 0; + + adc1213x[chip].end_conv = 0; + } +} + +void adc1213x_sclk_w(int chip, int state) +{ + if (state) + { + //printf("ADC: cycle %d, DI = %d\n", adc1213x[chip].cycle, adc1213x[chip].data_in); + + adc1213x[chip].input_shift_reg <<= 1; + adc1213x[chip].input_shift_reg |= adc1213x[chip].data_in; + + adc1213x[chip].data_out = adc1213x[chip].output_shift_reg & 1; + adc1213x[chip].output_shift_reg >>= 1; + + adc1213x[chip].cycle++; + } +} + +void adc1213x_conv_w(int chip, int state) +{ + adc1213x[chip].end_conv = 1; +} + +int adc1213x_eoc_r(int chip) +{ + return adc1213x[chip].end_conv; +} + +void adc1213x_init(int chip, double (*input_callback)( int input )) +{ + memset(&adc1213x[chip], 0, sizeof(ADC1213X)); + + adc1213x[chip].conv_mode = ADC1213X_CONV_MODE_12_MSB_FIRST; + adc1213x[chip].data_out_sign = 1; + adc1213x[chip].auto_cal = 0; + adc1213x[chip].auto_zero = 0; + adc1213x[chip].acq_time = ADC1213X_ACQUISITION_TIME_10_CCLK; + + adc1213x[chip].input_callback = input_callback; +} |