tmk
11 years ago
1 changed files with 39 additions and 15 deletions
+ 39
- 15
protocol/adb.c
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| { | { | ||||
| // ADB Bit Cells | // 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; | 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); | _delay_us(55); | ||||
| bit = data_in(); | 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; | return bit; | ||||
| } | } | ||||
| --------- | --------- | ||||
| ADB - The Untold Story: Space Aliens Ate My Mouse | ADB - The Untold Story: Space Aliens Ate My Mouse | ||||
| http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_01.html | http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_01.html | ||||
| Apple IIgs Hardware Reference Second Edition [p80(Chapter6 p121)] | |||||
| Apple IIgs Hardware Reference Second Edition [Chapter6 p121] | |||||
| ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf | ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf | ||||
| ADB Keycode | ADB Keycode | ||||
| http://72.0.193.250/Documentation/macppc/adbkeycodes/ | http://72.0.193.250/Documentation/macppc/adbkeycodes/ | ||||
| Global reset: | Global reset: | ||||
| Host asserts low in 2.8-5.2ms. All devices are forced to 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. | 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) | Keyboard Data(Register0) |