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author | balrog <balrog@c046a42c-6fe2-441c-8c8c-71466251a162> | 2007-04-30 02:14:00 +0000 |
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committer | balrog <balrog@c046a42c-6fe2-441c-8c8c-71466251a162> | 2007-04-30 02:14:00 +0000 |
commit | c824cacdb1aa8bfd9e057dd64b4b8a16f5727fff (patch) | |
tree | d759d74610a78d5d1710389b087a5c63ea81c564 /hw | |
parent | fd5a3b33d1f19b4859a8c528097abdbc4463e7e0 (diff) | |
download | hqemu-c824cacdb1aa8bfd9e057dd64b4b8a16f5727fff.zip hqemu-c824cacdb1aa8bfd9e057dd64b4b8a16f5727fff.tar.gz |
Maxim MAX1110/1111 ADC chip.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2755 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'hw')
-rw-r--r-- | hw/max111x.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/hw/max111x.c b/hw/max111x.c new file mode 100644 index 0000000..69019de --- /dev/null +++ b/hw/max111x.c @@ -0,0 +1,136 @@ +/* + * Maxim MAX1110/1111 ADC chip emulation. + * + * Copyright (c) 2006 Openedhand Ltd. + * Written by Andrzej Zaborowski <balrog@zabor.org> + * + * This code is licensed under the GNU GPLv2. + */ + +#include <vl.h> + +struct max111x_s { + qemu_irq interrupt; + uint8_t tb1, rb2, rb3; + int cycle; + + int input[8]; + int inputs, com; +}; + +/* Control-byte bitfields */ +#define CB_PD0 (1 << 0) +#define CB_PD1 (1 << 1) +#define CB_SGL (1 << 2) +#define CB_UNI (1 << 3) +#define CB_SEL0 (1 << 4) +#define CB_SEL1 (1 << 5) +#define CB_SEL2 (1 << 6) +#define CB_START (1 << 7) + +#define CHANNEL_NUM(v, b0, b1, b2) \ + ((((v) >> (2 + (b0))) & 4) | \ + (((v) >> (3 + (b1))) & 2) | \ + (((v) >> (4 + (b2))) & 1)) + +uint32_t max111x_read(void *opaque) +{ + struct max111x_s *s = (struct max111x_s *) opaque; + + if (!s->tb1) + return 0; + + switch (s->cycle ++) { + case 1: + return s->rb2; + case 2: + return s->rb3; + } + + return 0; +} + +/* Interpret a control-byte */ +void max111x_write(void *opaque, uint32_t value) +{ + struct max111x_s *s = (struct max111x_s *) opaque; + int measure, chan; + + /* Ignore the value if START bit is zero */ + if (!(value & CB_START)) + return; + + s->cycle = 0; + + if (!(value & CB_PD1)) { + s->tb1 = 0; + return; + } + + s->tb1 = value; + + if (s->inputs == 8) + chan = CHANNEL_NUM(value, 1, 0, 2); + else + chan = CHANNEL_NUM(value & ~CB_SEL0, 0, 1, 2); + + if (value & CB_SGL) + measure = s->input[chan] - s->com; + else + measure = s->input[chan] - s->input[chan ^ 1]; + + if (!(value & CB_UNI)) + measure ^= 0x80; + + s->rb2 = (measure >> 2) & 0x3f; + s->rb3 = (measure << 6) & 0xc0; + + if (s->interrupt) + qemu_irq_raise(s->interrupt); +} + +static struct max111x_s *max111x_init(qemu_irq cb) +{ + struct max111x_s *s; + s = (struct max111x_s *) + qemu_mallocz(sizeof(struct max111x_s)); + memset(s, 0, sizeof(struct max111x_s)); + + s->interrupt = cb; + + /* TODO: add a user interface for setting these */ + s->input[0] = 0xf0; + s->input[1] = 0xe0; + s->input[2] = 0xd0; + s->input[3] = 0xc0; + s->input[4] = 0xb0; + s->input[5] = 0xa0; + s->input[6] = 0x90; + s->input[7] = 0x80; + s->com = 0; + return s; +} + +struct max111x_s *max1110_init(qemu_irq cb) +{ + struct max111x_s *s = max111x_init(cb); + s->inputs = 8; + return s; +} + +struct max111x_s *max1111_init(qemu_irq cb) +{ + struct max111x_s *s = max111x_init(cb); + s->inputs = 4; + return s; +} + +void max111x_set_input(struct max111x_s *s, int line, uint8_t value) +{ + if (line >= s->inputs) { + printf("%s: There's no input %i\n", __FUNCTION__, line); + return; + } + + s->input[line] = value; +} |