Fix comment of ADB signaling.
This commit is contained in:
parent
4d4dd62fbb
commit
3d01fad0ce
@ -199,24 +199,48 @@ static inline bool read_bit(void)
|
|||||||
{
|
{
|
||||||
// ADB Bit Cells
|
// ADB Bit Cells
|
||||||
//
|
//
|
||||||
// bit0: ______~~~
|
|
||||||
// 65 :35us
|
|
||||||
//
|
|
||||||
// bit1: ___~~~~~~
|
|
||||||
// 35 :65us
|
|
||||||
//
|
|
||||||
// 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
|
// bit cell time: 70-130us
|
||||||
// [from Apple IIgs Hardware Reference Second Edition]
|
// low part of bit0: 60-70% of bit cell
|
||||||
|
// low part of bit1: 30-40% of bit cell
|
||||||
//
|
//
|
||||||
// After 55us if data line is low/high then bit is 0/1.
|
// bit cell time 70us 130us
|
||||||
// Too simple to rely on?
|
// --------------------------------------------
|
||||||
|
// 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:
|
||||||
|
// 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;
|
||||||
}
|
}
|
||||||
|
|
||||||
@ -258,7 +282,7 @@ Resources
|
|||||||
---------
|
---------
|
||||||
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/
|
||||||
@ -376,9 +400,9 @@ Communication
|
|||||||
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)
|
||||||
|
Reference in New Issue
Block a user