2 Copyright 2014 Jun WAKO <wakojun@gmail.com>
7 #define IBM4704_ERR_NONE 0
8 #define IBM4704_ERR_STARTBIT 1
9 #define IBM4704_ERR_PARITY 0x70
12 void ibm4704_init(void);
13 uint8_t ibm4704_send(uint8_t data);
14 uint8_t ibm4704_recv_response(void);
15 uint8_t ibm4704_recv(void);
18 /* Check pin configuration */
19 #if !(defined(IBM4704_CLOCK_PORT) && \
20 defined(IBM4704_CLOCK_PIN) && \
21 defined(IBM4704_CLOCK_DDR) && \
22 defined(IBM4704_CLOCK_BIT))
23 # error "ibm4704 clock pin configuration is required in config.h"
26 #if !(defined(IBM4704_DATA_PORT) && \
27 defined(IBM4704_DATA_PIN) && \
28 defined(IBM4704_DATA_DDR) && \
29 defined(IBM4704_DATA_BIT))
30 # error "ibm4704 data pin configuration is required in config.h"
34 /*--------------------------------------------------------------------
36 *------------------------------------------------------------------*/
37 static inline void clock_lo(void)
39 IBM4704_CLOCK_PORT &= ~(1<<IBM4704_CLOCK_BIT);
40 IBM4704_CLOCK_DDR |= (1<<IBM4704_CLOCK_BIT);
42 static inline void clock_hi(void)
44 /* input with pull up */
45 IBM4704_CLOCK_DDR &= ~(1<<IBM4704_CLOCK_BIT);
46 IBM4704_CLOCK_PORT |= (1<<IBM4704_CLOCK_BIT);
48 static inline bool clock_in(void)
50 IBM4704_CLOCK_DDR &= ~(1<<IBM4704_CLOCK_BIT);
51 IBM4704_CLOCK_PORT |= (1<<IBM4704_CLOCK_BIT);
53 return IBM4704_CLOCK_PIN&(1<<IBM4704_CLOCK_BIT);
55 static inline void data_lo(void)
57 IBM4704_DATA_PORT &= ~(1<<IBM4704_DATA_BIT);
58 IBM4704_DATA_DDR |= (1<<IBM4704_DATA_BIT);
60 static inline void data_hi(void)
62 /* input with pull up */
63 IBM4704_DATA_DDR &= ~(1<<IBM4704_DATA_BIT);
64 IBM4704_DATA_PORT |= (1<<IBM4704_DATA_BIT);
66 static inline bool data_in(void)
68 IBM4704_DATA_DDR &= ~(1<<IBM4704_DATA_BIT);
69 IBM4704_DATA_PORT |= (1<<IBM4704_DATA_BIT);
71 return IBM4704_DATA_PIN&(1<<IBM4704_DATA_BIT);
74 static inline uint16_t wait_clock_lo(uint16_t us)
76 while (clock_in() && us) { asm(""); _delay_us(1); us--; }
79 static inline uint16_t wait_clock_hi(uint16_t us)
81 while (!clock_in() && us) { asm(""); _delay_us(1); us--; }
84 static inline uint16_t wait_data_lo(uint16_t us)
86 while (data_in() && us) { asm(""); _delay_us(1); us--; }
89 static inline uint16_t wait_data_hi(uint16_t us)
91 while (!data_in() && us) { asm(""); _delay_us(1); us--; }
95 /* idle state that device can send */
96 static inline void idle(void)
102 /* inhibit device to send
103 * keyboard checks Data line on start bit(Data:hi) and it stops sending if Data line is low.
105 static inline void inhibit(void)