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97a46a7b9b
My idea of plugging a RC2014 bridge directly onto a Sega Master System cartridge doesn't work. The SMS eats all I/O addr space, we can't use it. Therefore, this naive idea, in the emulator, of reusing sdc.c in sms.c as-is, doesn't work either. I'll have to find another way of communicating to a SPI device on the SMS. I'll probably do it through a controller port. Meanwhile, I need to decouple SPI from SDC in the emulator code so that I can reuse sdc.c. This is what is done here.
30 lines
1018 B
C
30 lines
1018 B
C
#include "emul.h"
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typedef struct {
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// Initialization status. 0 == not woken 8 == woken 9 == CMD0 received
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// 10 == CMD8 received, 11 == CMD55 received, 12 == CMD41 received (fully
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// initialized).
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unsigned int initstat;
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// We receive commands into this buffer.
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byte recvbuf[6];
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// Where the next SPI byte should be stored in recvbuf.
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unsigned int recvidx;
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// Buffer to the arguments for a response
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byte sendbuf[5];
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// Index of the next byte from sendbuf we should return. If -1, buffer is
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// empty.
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int sendidx;
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// File used for contents read/write
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FILE *fp;
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// number of bytes read into the current CMD17. -1 means no CMD17 active.
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int cmd17bytes;
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// number of bytes received for the current CMD24. -2 means no CMD24 active.
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// -1 means we're still waiting for the data token.
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int cmd24bytes;
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// running crc16 during read and write operations.
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uint16_t crc16;
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} SDC;
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void sdc_init(SDC *sdc);
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byte sdc_spix(SDC *sdc, byte val);
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