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37 lines
1.0 KiB
C
37 lines
1.0 KiB
C
#include <string.h>
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#include <hardware/pio.h>
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#include "common/config.h"
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#include "abus.pio.h"
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#include "parallel/businterface.h"
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#include "parallel/parallelbuffer.h"
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volatile uint8_t parallel_tx_reg = 0x00;
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volatile uint8_t parallel_strobe = 0x00;
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static inline void __time_critical_func(parallel_write)(uint32_t address, uint32_t value) {
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uint8_t last_strobe = parallel_strobe;
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if(address & 0x1) {
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parallel_tx_reg = value;
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}
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if(address & 0x2) {
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parallel_strobe = 1;
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}
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if((last_strobe == 0) && (parallel_strobe == 1)) {
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parallel_tx_push(parallel_tx_reg);
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}
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if(address & 0x4) {
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parallel_strobe = 0;
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}
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}
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void __time_critical_func(parallel_businterface)(uint32_t address, uint32_t value) {
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// Shadow parts of the Apple's memory by observing the bus write cycles
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if((CARD_SELECT) && (CARD_DEVSEL) && ((value & (1u << CONFIG_PIN_APPLEBUS_RW-CONFIG_PIN_APPLEBUS_DATA_BASE)) == 0)) {
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parallel_write(address, value);
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}
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}
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