Lines Matching +full:- +full:uart

1 .\"-
2 .\" SPDX-License-Identifier: BSD-2-Clause
32 .Nm uart
35 .Cd "device uart"
38 .Cd "device uart"
41 .Cd "device uart"
45 .Cd hint.uart.0.disabled="1"
46 .Cd hint.uart.0.baud="38400"
47 .Cd hint.uart.0.port="0x3f8"
48 .Cd hint.uart.0.flags="0x10"
53 .Bl -tag -compact -width 0x000000
72 EIA RS-232C (CCITT V.24) serial communications interface.
112 It contains the bus attachments and the low-level interrupt handler.
124 Such an UART cannot be used for general purpose communications.
126 corresponding UART will in turn be a system device so that the kernel can
131 This component ultimately determines how the UART is made visible to the
134 This allows the UART to be used for terminals, modems and serial line IP
144 .Bl -bullet -compact
169 .Va hw.uart.pps_mode
170 tunable configures the PPS capture mode for all uart devices;
174 .Va dev.uart.0.pps_mode
175 sysctl configures the PPS capture mode for a specific uart device;
182 .Bl -tag -compact -offset "mmmm" -width "mmmm"
193 .Bl -tag -compact -offset "mmmm" -width "mmmm"
195 Invert the pulse (RS-232 logic low = ASSERT, high = CLEAR).
214 Add the invert option when the connection to the uart device uses TTL
216 RFC 2783 defines an ASSERT event as a higher-voltage line level, and a CLEAR
217 event as a lower-voltage line level, in the context of the RS-232 protocol.
218 The modem control signals on a TTL-level connection are typically
219 inverted from the RS-232 levels.
220 For example, carrier presence is indicated by a high signal on an RS-232
223 TTL and RS-232 line levels in most hardware designs.
224 Generally speaking, a connection to a DB-9 style connector is an RS-232
226 A connection to header pins or an edge-connector on an embedded board
231 driver also supports an initial-state and a lock-state control
234 from those of the corresponding initial-state device
238 in the normal way on the initial-state devices to program
245 on the lock-state device.
247 may be locked by setting the corresponding value in the lock-state
251 on the initial-state device and
253 on the lock-state device.
278 .Bl -tag -width indent
279 .It Va hw.uart.console
283 .Bl -tag -width indent
286 Enable the so-called
289 For NS 16550-compatible devices, this will use heuristics to ensure that the
290 UART is no longer busy before manipulating line control.
291 DesignWare-based UARTs need this due to a design flaw in the UART.
304 driver to not program the baud rate divisor and use the hardware as-is.
314 Specify the uart class to use for this device.
315 .Bl -tag -width indent
317 Traditional PC UART National Semiconductor 16550 and compatible devices.
319 Common ARM UART, based on ARM Limited designs.
323 Specifies the address of a UART in an Intel processor's I/O space.
328 Specifies the physical address of a memory-mapped UART.
351 When set to 0, and the baud rate is also set, the UART's initialization
358 .Bl -tag -width "/dev/ttyu?.init" -compact
363 corresponding callin initial-state and lock-state devices
369 corresponding callout initial-state and lock-state devices
372 .Dl hw.uart.console="io:0x2f8,br=115200"