diff options
| author | imp <imp@FreeBSD.org> | 2005-12-05 23:30:28 +0000 |
|---|---|---|
| committer | imp <imp@FreeBSD.org> | 2005-12-05 23:30:28 +0000 |
| commit | bf26ea247407f098c35c06dd1766ae53eaa35043 (patch) | |
| tree | d9701b90b438433105b2c040bb7fde4433194395 /sys/dev/puc | |
| parent | 0fcccb0032586c0136de2c3376457c321dbfb1ed (diff) | |
| download | FreeBSD-src-bf26ea247407f098c35c06dd1766ae53eaa35043.zip FreeBSD-src-bf26ea247407f098c35c06dd1766ae53eaa35043.tar.gz | |
The Oxford 16C950 based CardBus Serial device that I was given some
time ago appears to be based not on the typical 1.8432MHz clock, or
the other more typical multiple of 8 of this (14.7456MHz), but instead
it appears to be 1/2 the PCI clock rate or 16.50000MHz. I'm not 100%
sure that this is right, but since I did the original entry, I'm going
to go ahead and modify it. With the 14.7456MHz value, I was getting
bits that were ~7.3us instead of ~8.6us like they are supposed to be.
My measuring gear for today is a stupid handheld scope with two
signficant digits. So I don't know if it is 33.000000/2 MHz or some
other value close to 16.5MHz, but 16.5MHz works well enough for me to
use a couple of different devices at 115200 baud, and is a nice even
multiple of a well known clock frequency...
Diffstat (limited to 'sys/dev/puc')
| -rw-r--r-- | sys/dev/puc/pucdata.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sys/dev/puc/pucdata.c b/sys/dev/puc/pucdata.c index a0804f1..6e4bf27 100644 --- a/sys/dev/puc/pucdata.c +++ b/sys/dev/puc/pucdata.c @@ -884,7 +884,8 @@ const struct puc_device_description puc_devices[] = { { 0x1415, 0x950b, 0, 0 }, { 0xffff, 0xffff, 0, 0 }, { - { PUC_PORT_TYPE_COM, 0x10, 0x00, COM_FREQ }, + /* { PUC_PORT_TYPE_COM, 0x10, 0x00, COM_FREQ }, */ + { PUC_PORT_TYPE_COM, 0x10, 0x00, 33000000 / 2}, }, }, |
