using the bootstrap loader

CONFIGURING THE FIRST STAGE
3-22
counter _base yort
counter yort_ delta
baud counter
count
The 16-bit port address of the base port used by the
baud rate timer. The port whose address you specify
varies according to the type of timer device and, if
applicable, the channel used on the device. The following
list shows the ports for each of the valid timers. Specify
the address of the port that corresponds to your timer
device. The hardware reference manual for the CPU
board lists the port addresses for these serial devices.
Timer Type
8253
8254
80130
80186
82530 Channel A
82530 Channel B
Base Port
Counter 0 Count Register Port
Counter 0 Count Register Port
ICW1 Register Port
Use OFFOOH for all boards
Channel A Command Register
Port
Channel B Command Register
Port
The number of bytes separating consecutive ports used
by the timer.
The number of the counter that is used for baud-rate
generation. The following list identifies the possible
counter numbers you can specify for each of the timers.
Timer Type
8253
8254
80130
80186
82530
Counter Numbers
0,1, or 2
0,1, or 2
2
o or 1
o
A value that when loaded into the timer register
generates the desired baud rate. The method of
calculating this value follows these parameter
definitions.
Bootstrap Loader