mirror of
https://github.com/hsoft/collapseos.git
synced 2024-12-27 20:28:05 +11:00
40 lines
1.3 KiB
C
40 lines
1.3 KiB
C
|
#include <stdint.h>
|
||
|
|
#include <stdbool.h>
|
||
|
|
|
||
|
|
typedef struct {
|
||
|
|
// Bit 7: interrupt status, low when interrupt request pending.
|
||
|
|
// Bit 6: Parity error
|
||
|
|
// Bit 5: Receiver overrun
|
||
|
|
// Bit 4: Framing error
|
||
|
|
// Bit 3: Clear To Send
|
||
|
|
// Bit 2: Data Carrier Detected
|
||
|
|
// Bit 1: Transmit Data Register Empty (TDRE)
|
||
|
|
// Bit 0: Receive Data Register Full (RDRF)
|
||
|
|
// We care about bits 7, 1, 0, maybe 5 later.
|
||
|
|
uint8_t status;
|
||
|
|
// Bit 7: interrupt enable
|
||
|
|
// Bits 6:5: RTS + transmit interrupt enable
|
||
|
|
// Bits 4:2: parity + stop bit
|
||
|
|
// Bits 1:0: speed divider
|
||
|
|
// We don't actually care about any of those except the interrupt enable
|
||
|
|
// bits.
|
||
|
|
uint8_t control;
|
||
|
|
uint8_t rx;
|
||
|
|
uint8_t tx;
|
||
|
|
// Will be set to true the first time acia_has_irq() is called when IRQ is
|
||
|
|
// set. Then, as long as it stays true, acia_has_irq() will return false.
|
||
|
|
// When IRQ status is reset, so is in_int.
|
||
|
|
bool in_int;
|
||
|
|
} ACIA;
|
||
|
|
|
||
|
|
void acia_init(ACIA *acia);
|
||
|
|
bool acia_has_irq(ACIA *acia);
|
||
|
|
bool acia_hasrx(ACIA *acia);
|
||
|
|
bool acia_hastx(ACIA *acia);
|
||
|
|
uint8_t acia_read(ACIA *acia);
|
||
|
|
void acia_write(ACIA *acia, uint8_t val);
|
||
|
|
uint8_t acia_ctl_rd(ACIA *acia);
|
||
|
|
void acia_ctl_wr(ACIA *acia, uint8_t val);
|
||
|
|
uint8_t acia_data_rd(ACIA *acia);
|
||
|
|
void acia_data_wr(ACIA *acia, uint8_t val);
|