2 #include <util/delay.h>
7 static inline void data_lo(void);
8 static inline void data_hi(void);
9 static inline bool data_in(void);
11 static inline void psw_lo(void);
12 static inline void psw_hi(void);
13 static inline bool psw_in(void);
16 static inline void attention(void);
17 static inline void place_bit0(void);
18 static inline void place_bit1(void);
19 static inline void send_byte(uint8_t data);
20 static inline bool read_bit(void);
21 static inline uint8_t read_byte(void);
22 static inline uint8_t wait_data_lo(uint8_t us);
23 static inline uint8_t wait_data_hi(uint8_t us);
26 void adb_host_init(void)
35 bool adb_host_psw(void)
41 uint16_t adb_host_kbd_recv(void)
45 send_byte(0x2C); // Addr:Keyboard(0010), Cmd:Talk(11), Register0(00)
46 place_bit0(); // Stopbit(0)
47 if (!wait_data_lo(0xFF)) // Tlt/Stop to Start(140-260us)
48 return 0; // No data to send
49 if (!read_bit()) // Startbit(1)
52 data = (data<<8) | read_byte();
53 if (read_bit()) // Stopbit(0)
59 void adb_host_kbd_led(uint8_t led)
62 send_byte(0x2A); // Addr:Keyboard(0010), Cmd:Listen(10), Register2(10)
63 place_bit0(); // Stopbit(0)
64 _delay_us(200); // Tlt/Stop to Start
65 place_bit1(); // Startbit(1)
66 send_byte(0); // send upper byte (not used)
67 send_byte(led&0x07); // send lower byte (bit2: ScrollLock, bit1: CapsLock, bit0: NumLock)
68 place_bit0(); // Stopbit(0);
72 static inline void data_lo()
74 ADB_DDR |= (1<<ADB_DATA_BIT);
75 ADB_PORT &= ~(1<<ADB_DATA_BIT);
77 static inline void data_hi()
79 ADB_PORT |= (1<<ADB_DATA_BIT);
80 ADB_DDR &= ~(1<<ADB_DATA_BIT);
82 static inline bool data_in()
84 ADB_PORT |= (1<<ADB_DATA_BIT);
85 ADB_DDR &= ~(1<<ADB_DATA_BIT);
86 return ADB_PIN&(1<<ADB_DATA_BIT);
90 static inline void psw_lo()
92 ADB_DDR |= (1<<ADB_PSW_BIT);
93 ADB_PORT &= ~(1<<ADB_PSW_BIT);
95 static inline void psw_hi()
97 ADB_PORT |= (1<<ADB_PSW_BIT);
98 ADB_DDR &= ~(1<<ADB_PSW_BIT);
100 static inline bool psw_in()
102 ADB_PORT |= (1<<ADB_PSW_BIT);
103 ADB_DDR &= ~(1<<ADB_PSW_BIT);
104 return ADB_PIN&(1<<ADB_PSW_BIT);
108 static inline void attention(void)
115 static inline void place_bit0(void)
123 static inline void place_bit1(void)
131 static inline void send_byte(uint8_t data)
133 for (int i = 0; i < 8; i++) {
141 static inline bool read_bit(void)
151 // bit0 low time: 60-70% of bit cell(42-91us)
152 // bit1 low time: 30-40% of bit cell(21-52us)
153 // bit cell time: 70-130us
154 // [from Apple IIgs Hardware Reference Second Edition]
156 // After 55us if data line is low/high then bit is 0/1.
157 // Too simple to rely on?
159 wait_data_lo(75); // wait the beginning of bit cell
162 wait_data_hi(36); // wait high part of bit cell
166 static inline uint8_t read_byte(void)
169 for (int i = 0; i < 8; i++) {
177 static inline uint8_t wait_data_lo(uint8_t us)
179 while (data_in() && us) {
186 static inline uint8_t wait_data_hi(uint8_t us)
188 while (!data_in() && us) {