Lines Matching +full:use +full:- +full:handshake

1 .\" -*- nroff -*-
3 .\" Copyright (c) 1996 A.R.Gordon, andrew.gordon@net-tel.co.uk
6 .\" Redistribution and use in source and binary forms, with or without
24 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 point-to-point network interface between two similarly configured systems.
54 and any standard AT-compatible printer port with working interrupts may be used.
73 .Bl -tag -width Fl
75 (default) Use
91 .Bd -literal
93 	2	15	Data0 -> ERROR*
94 	3	13	Data1 -> SLCT
95 	4	12	Data2 -> PE
96 	5	10	Data3 -> ACK*
97 	6	11	Data4 -> BUSY
98 	15	2	ERROR* -> Data0
99 	13	3	SLCT   -> Data1
100 	12	4	PE     -> Data2
101 	10	5	ACK*   -> Data3
102 	11	6	BUSY   -> Data4
103 	18-25	18-25	Ground
110 data plus one handshake).
111 The two modes use the same wiring, but make a
112 different choice of which line to use as handshake.
115 .Bl -tag -width dataxxxx(Pinxx)
123 Handshake out.
135 Handshake in.
140 sender writes the 4 most significant bits and raises the handshake line;
141 receiver reads the 4 bits and raises its handshake to acknowledge;
143 the handshake; receiver reads the data and lowers its handshake.
145 The packet format has a two-byte header, comprising the fixed values 0x08,
151 the data lines (i.e., writing the ones-complement of the previous nibble
152 to be transmitted) without changing the state of the handshake.
154 Note that the end-of-packet marker assumes that the handshake signal and
155 the data-out bits can be written in a single instruction - otherwise
157 as end-of-packet.
162 .Bl -tag -width dataxxxx(Pinxx)
172 Handshake out.
182 Handshake in.
187 sender writes the 4 least significant bits and raises the handshake line;
188 receiver reads the 4 bits and raises its handshake to acknowledge;
190 the handshake; receiver reads the data and lowers its handshake.
194 .Bd -literal
214 for handshake-in cannot be used to generate an interrupt.
228 Busy-waiting loops are used while handshaking bytes, (and worse still when
234 due to the choice of handshake lines; it could theoretically be improved