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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [libchip/] [serial/] [README.ns16550] - Rev 173
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#
# $Id: README.ns16550,v 1.2 2001-09-27 12:01:42 chris Exp $
#
Status
======
This driver appears to work OK for polled output at this point.
It needs to be tested for:
+ polled input
+ interrupt driver output
+ interrupt driver input
This driver does not support the new style RTEMS interrupt processing
used on the i386 and some PowerPC models.
Configuration Table Use
=======================
sDeviceName
The name of this device.
deviceType
This field must be SERIAL_NS16550.
pDeviceFns
The device interface control table. This may be:
+ ns16550_fns for interrupt driven IO
+ ns16550_fns_polled for polled IO
deviceProbe
This is the address of the routine which probes to see if the device
is present.
pDeviceFlow
This field is ignored as hardware flow control is not currently supported.
ulMargin
This is currently unused.
ulHysteresis
This is currently unused.
pDeviceParams
This is set to the default settings. At this point, it is the default
baud rate cast as a (void *).
ulCtrlPort1
This field is the base address of this port on the UART.
ulCtrlPort2
This field is unused for the NS16550.
ulDataPort
This field is the base address of this port on the UART.
getRegister
setRegister
These follow standard conventions.
getData
setData
These are unused since the TX and RX data registers can be accessed
as regular registers.
ulClock
This is the clock constant which is divided by the desired baud
to get the value programmed into the part. The formula for this
for 9600 baud is:
chip_divisor_value = ulClock / 9600.
NOTE: When ulClock is 0, the correct value for a PC (115,200) is
used.
ulIntVector
This is the interrupt vector number associated with this chip.