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-rw-r--r--protocol/adb.c73
1 files changed, 53 insertions, 20 deletions
diff --git a/protocol/adb.c b/protocol/adb.c
index 9e8d76832d..2f3f667b79 100644
--- a/protocol/adb.c
+++ b/protocol/adb.c
@@ -57,12 +57,13 @@ static inline void place_bit1(void);
static inline void send_byte(uint8_t data);
static inline bool read_bit(void);
static inline uint8_t read_byte(void);
-static inline uint8_t wait_data_lo(uint8_t us);
+static inline uint8_t wait_data_lo(uint16_t us);
static inline uint8_t wait_data_hi(uint8_t us);
void adb_host_init(void)
{
+DDRF |= (1<<1);
data_hi();
#ifdef ADB_PSW_BIT
psw_hi();
@@ -88,19 +89,24 @@ uint16_t adb_host_kbd_recv(void)
attention();
send_byte(0x2C); // Addr:Keyboard(0010), Cmd:Talk(11), Register0(00)
place_bit0(); // Stopbit(0)
- if (!wait_data_lo(0xFF)) // Tlt/Stop to Start(140-260us)
+ if (!wait_data_lo(500)) { // Tlt/Stop to Start(140-260us)
return 0; // No data to send
- if (!read_bit()) // Startbit(1)
+ }
+ if (!read_bit()) { // Startbit(1)
+ // Service Request
return -2;
+ }
// ad hoc fix: without block inerrupt read wrong bit occasionally and get keys stuck
cli();
data = read_byte();
data = (data<<8) | read_byte();
+ uint8_t stop = read_bit(); // Stopbit(0)
sei();
- if (read_bit()) // Stopbit(0)
+ if (stop) {
return -3;
+ }
return data;
}
@@ -199,24 +205,48 @@ static inline bool read_bit(void)
{
// ADB Bit Cells
//
- // bit0: ______~~~
- // 65 :35us
+ // bit cell time: 70-130us
+ // low part of bit0: 60-70% of bit cell
+ // low part of bit1: 30-40% of bit cell
//
- // bit1: ___~~~~~~
- // 35 :65us
+ // bit cell time 70us 130us
+ // --------------------------------------------
+ // low part of bit0 42-49 78-91
+ // high part of bit0 21-28 39-52
+ // low part of bit1 21-28 39-52
+ // high part of bit1 42-49 78-91
//
- // bit0 low time: 60-70% of bit cell(42-91us)
- // bit1 low time: 30-40% of bit cell(21-52us)
- // bit cell time: 70-130us
- // [from Apple IIgs Hardware Reference Second Edition]
//
- // After 55us if data line is low/high then bit is 0/1.
- // Too simple to rely on?
+ // bit0:
+ // 70us bit cell:
+ // ____________~~~~~~
+ // 42-49 21-28
+ //
+ // 130us bit cell:
+ // ____________~~~~~~
+ // 78-91 39-52
+ //
+ // bit1:
+ // 70us bit cell:
+ // ______~~~~~~~~~~~~
+ // 21-28 42-49
+ //
+ // 130us bit cell:
+ // ______~~~~~~~~~~~~
+ // 39-52 78-91
+ //
+ // read:
+ // ________|~~~~~~~~~
+ // 55us
+ // Read data line after 55us. If data line is low/high then bit is 0/1.
+ // This method might not work at <90us bit cell time.
+ //
+ // [from Apple IIgs Hardware Reference Second Edition]
bool bit;
- wait_data_lo(75); // wait the beginning of bit cell
+ wait_data_lo(75); // wait the start of bit cell at least 130ms(55+0+75)
_delay_us(55);
bit = data_in();
- wait_data_hi(36); // wait high part of bit cell
+ wait_data_hi(36); // wait high part of bit cell at least 91ms(55+36)
return bit;
}
@@ -231,7 +261,7 @@ static inline uint8_t read_byte(void)
return data;
}
-static inline uint8_t wait_data_lo(uint8_t us)
+static inline uint8_t wait_data_lo(uint16_t us)
{
while (data_in() && us) {
_delay_us(1);
@@ -258,7 +288,10 @@ Resources
---------
ADB - The Untold Story: Space Aliens Ate My Mouse
http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_01.html
-Apple IIgs Hardware Reference Second Edition [p80(Chapter6 p121)]
+ADB Manager
+ http://developer.apple.com/legacy/mac/library/documentation/mac/pdf/Devices/ADB_Manager.pdf
+ Service request(5-17)
+Apple IIgs Hardware Reference Second Edition [Chapter6 p121]
ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf
ADB Keycode
http://72.0.193.250/Documentation/macppc/adbkeycodes/
@@ -376,9 +409,9 @@ Communication
Global reset:
Host asserts low in 2.8-5.2ms. All devices are forced to reset.
- Send request from device(Srq):
+ Service request from device(Srq):
Device can request to send at commad(Global only?) stop bit.
- keep low for 300us to request.
+ Requesting device keeps low for 140-260us at stop bit of command.
Keyboard Data(Register0)