Lines Matching +full:baud +full:- +full:rate
1 .. SPDX-License-Identifier: GPL-2.0
10 The baud rate produced by the baud generator is obtained from this input
12 value from 1 to 63.875 in increments of 0.125, and then the usual 16-bit
14 value from 1 to 65535. Finally a programmable oversampling rate is used
16 determine the actual baud rate used. Baud rates from 15625000bps down
19 By default the oversampling rate is set to 16 and the clock prescaler is
21 for the usual 16-bit divisor is 115313.653, which is close enough to the
23 used for the divisor to obtain the requested baud rates by software that
26 The oversampling rate is programmed with the TCR register and the clock
38 obtained, with either exact or highly-accurate actual bit rates for
39 standard and many non-standard rates.
41 Here are the figures for the standard and some non-standard baud rates
43 the requested rate (r), the actual rate yielded (a) and its deviation
44 from the requested rate (d), and the values of the oversampling rate
56 r: 3686400, a: 3676470.59, d: -0.2694%, tcr: 8, cpr: 2.125, div: 1
57 r: 3500000, a: 3496503.50, d: -0.0999%, tcr: 13, cpr: 1.375, div: 1
58 r: 3000000, a: 2976190.48, d: -0.7937%, tcr: 14, cpr: 1.500, div: 1
61 r: 1843200, a: 1838235.29, d: -0.2694%, tcr: 16, cpr: 2.125, div: 1
62 r: 1500000, a: 1492537.31, d: -0.4975%, tcr: 5, cpr: 8.375, div: 1
64 r: 921600, a: 919117.65, d: -0.2694%, tcr: 16, cpr: 2.125, div: 2
73 r: 4800, a: 4799.98, d: -0.0004%, tcr: 7, cpr: 2.875, div: 647
88 With the baud base set to 15625000 and the unsigned 16-bit UART_DIV_MAX
89 limitation imposed by ``serial8250_get_baud_rate`` standard baud rates
90 below 300bps become unavailable in the regular way, e.g. the rate of
91 200bps requires the baud base to be divided by 78125 and that is beyond
92 the unsigned 16-bit range. The historic spd_cust feature can still be
93 used by encoding the values for, the prescaler, the oversampling rate
100 +-----+-----------------+-------+-------------------------------+
102 +-----+-----------------+-------+-------------------------------+
108 the baud rate of 38400bps. Note that the value of 0 in TCR sets the
109 oversampling rate to 16 and prescaler values below 1 in CPR2/CPR are
114 the oversampling rate and the clock divisor of 62.500, 16 and 1250
115 respectively. These parameters will set the baud rate for the serial
120 .. [OX200] "OXPCIe200 PCI Express Multi-Port Bridge", Oxford Semiconductor,
121 Inc., DS-0045, 10 Nov 2008, Section "950 Mode", pp. 64-65
124 Oxford Semiconductor, Inc., DS-0046, Mar 06 08, Section "950 Mode",
128 Semiconductor, Inc., DS-0047, Feb 08, Section "950 Mode", p. 20
131 Semiconductor, Inc., DS-0048, Feb 08, Section "950 Mode", p. 20