Lines Matching +full:peripheral +full:- +full:to +full:- +full:memory

14 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
42 system provides a uniform, modular and architecture-independent
43 system for the implementation of drivers to control various parallel devices,
44 and to utilize different parallel port chipsets.
46 In order to write new drivers or port existing drivers, the ppbus system
48 .Bl -bullet -offset indent
50 architecture-independent macros or functions to access parallel ports
52 mechanism to allow various devices to share the same parallel port
57 with kernel-in drivers.
60 The ppbus system has been designed to support the development of standard
61 and non-standard software:
63 .Bl -column "Driver" -compact
67 .It Sy lpbb Ta "Philips official parallel port I2C bit-banging interface"
70 Another approach to the ppbus system is to port existing drivers.
73 .Bl -column "Driver" -compact
85 The ppbus system provides functions and macros to allocate a new
86 parallel port bus, then initialize it and upper peripheral device drivers.
89 functions to initialize the ppbus system.
96 But, for another architecture, accesses to one of our logical
100 .Bl -bullet -offset indent
104 bidirectional 8/4-bits mode, also called NIBBLE mode
115 This mode defines the protocol used by most PCs to transfer data to a printer.
118 generated by the software to clock the data to the printer.
120 Many I/O controllers have implemented a mode that uses a FIFO buffer to
122 This mode is referred to as
125 The NIBBLE mode is the most common way to get reverse channel data from a
126 printer or peripheral.
127 Combined with the standard host to printer mode, it
130 In this mode, outputs are 8-bits long.
136 any transfer is 8-bits long.
142 adapter and the peripheral.
145 .Bl -item -offset indent
154 The EPP protocol was originally developed as a means to provide a high
168 operate at close to the same performance levels as an equivalent ISA plug-in
175 peripheral vendors may implement protocol handshake with the following
177 Try to know how these lines toggle
178 with your peripheral, allowing the peripheral to request more data, stop the
181 At any time, the peripheral may interrupt the host with the nAck signal without
188 .Sh IEEE1284-1994 Standard
191 Bidirectional Parallel Peripheral Interface for Personal Computers".
196 also specifies a format for a peripheral identification string and a method of
197 returning this string to the host outside of the bidirectional data stream.
201 One should refer to architecture specific documentation in
202 order to manipulate machine dependent registers, mapped memory or other
203 methods to control these signals.
207 The computer acts as master and the peripheral as slave.
210 It allows software to
214 Any other mode must be firstly negotiated by the host to check
215 it is supported by the peripheral, then to enter one of the forward idle
218 At any time, the slave may want to send data to the host.
222 host must have previously negotiated to permit the peripheral to
224 Interrupt lines may be dedicated to the requesting signals
227 But peripheral requests are only a hint to the master host.
232 terminate the transfer or the slave may drive wires to signal that no more
242 you still have to request the ppbus when you want to access it, the negotiate
252 model to the underlying hardware.
256 layer that provides functions to:
257 .Bl -enum -offset indent
259 share the parallel port bus among the daisy-chain like connected devices
261 manage devices linked to ppbus
263 propose an arch-independent interface to access the hardware layer.
268 layer gathers the parallel peripheral device drivers.
270 We have to differentiate operating modes at various ppbus system layers.
275 native mode to any other mode emulated with extended modes without
280 This architecture should support IEEE1284-1994 modes.
290 ppbus attachment tries to detect any PnP parallel peripheral (according to
292 draft from (c)1993-4 Microsoft Corporation)
295 During probe, device drivers are supposed to request the ppbus and try to
300 ppbus allocation is mandatory not to corrupt I/O of other devices.
302 usage of ppbus allocation is to reserve the port and receive incoming
305 High level interrupt handlers are connected to the ppbus system thanks to the
311 But, in order to attach a handler, drivers must
313 Consequently, a ppbus request is mandatory in order to call the above
319 is a general purpose mechanism to allow fast low-level
321 Microsequences may be used to do either
322 standard (in IEEE1284 modes) or non-standard transfers.
324 microsequences is to avoid the overhead of the ppbus layer and do most of