Artesyn BajaPPC-750, User Manual

Page: 192 / 215

Standard Artesyn Functions 10-53
0002M621-15
Both serial ports can be configured to use 5 to 8 data bits, 1 or 2 stop bits, the
handshake control lines, and odd, even, or no parity.
10.15.6 Exceptions
SYNOPSIS
vectinit(HANDLER default_handler
HANDLERPARAM default_param,
unsigned long vectmask)
void connecthandler(unsigned long Vector, HANDLER handler)
void disconnecthandler(unsigned long Vector)
void Probe(char DirFlag,
char SizeFlag,
unsigned long Address,
unsigned long DataPtr)
DESCRIPTION
These processor-specific functions provide interrupt and exception handling
support.
The lower 2000
16
bytes of memory contain routines, which the processor exe-
cutes upon receiving an interrupt. These routines comprise the low memory
interrupt table. For example, upon receiving a vector 200
16
interrupt, the pro-
cessor branches to address 200
16
in memory and executes the corresponding
interrupt routine. The function vectinit initializes these routines in the inter-
rupt table so that they reference an unexpected-interrupt handler. vectinit
expects a pointer to the default unexpected-interrupt handler and an
optional fixed parameter for the handler. This ensures that the board will not
hang upon receiving unexpected interrupts. The unexpected-interrupt han-
dler saves the state of the processor at the point of detection and then calls
IntrErr , which displays the error and restarts the monitor. For those applica-
tions requiring an interrupt vector to perform only a simple task, vectinit
has a third parameter. This parameter, vectmask , specifies which vectors to ini-
tialize and which vectors to leave unmodified in low memory. The parameter
is a 32-bit value, where each set bit indicates that the corresponding routine
should be replaced. For example, if
vectmask contains FFFF,FFFE
16
, all 32 vec-
tor routines will be overwritten except the routine at address 0
16
. If vectmask
contains FFFF,FFF3
16
, all the routines will be overwritten except those at
addresses 200
16
and 300
16
.
The function connecthandler initializes the entry in the vector table to
point to the Handler address. The argument Vector indicates the vector num-
ber to be connected and the argument Handler is the address of the function
that will handle the interrupts. With this structure, assembly language pro-
gramming for interrupts is avoided.