User Guide

Hardware and Software Design • Manufacturing Services
P a g e 14
Programming
Programming the PMC BiSerial-II PS2 requires only the ability to read and write
data from the host. The base address is determined during system configuration
of the PCI bus. The base address refers to the first user address for the slot in
which the PMC is installed.
Depending on the software environment it may be necessary to set-up the system
software with the PMC BiSerial-II "registration" data. For example in WindowsNT
there is a system registry, which is used to identify the resident hardware.
In order to receive data the software is only required to enable the Rx FIFO, and
Rx state machine for the channels of interest. To transmit the software will need
to load the message into the appropriate channel FIFO, set the frequency and
enable the transmitter.
The interrupt service routine should be loaded and the interrupt mask set. The
interrupt service routine can be configured to respond to the channel interrupts,
the COS interrupts or both. After the interrupt is received, the data can be
retrieved. An efficient loop can then be implemented to fetch the data. New
messages can be received even as the current one is read from the FIFO.
The TX interrupt indicates to the software that a message has been sent and that
the message has completed. If more than one interrupt is enabled, then the SW
needs to read BIS2_STAT1 to see which source caused the interrupt. The status
bits of BIS2_STAT1 are latched and are explicitly cleared by writing a one to the
corresponding bit. It is a good idea to read the status register and write that
value back to clear all the latched interrupt status bits before starting a transfer.
This will insure that the interrupt status values read by the interrupt service
routine came from the current transfer.
Refer to the Theory of Operation section above and the Interrupts section below
for more information regarding the exact sequencing and interrupt definitions.