OP7100
54
Software
The sample program OP71.C below cycles through through the outputs
with one bit high at a time while it displays the state of the digital inputs.
Real-Time Clock (RTC)
The OP7100 has an Epson 72423 chip. The chip stores time and date, and
accounts for the number of days in a month, and for leap year. A backup
battery will allow the values in the RTC to be preserved if a power failure
occurs.
The Dynamic C function library DRIVERS.LIB provides the following
RTC functions.
The Dynamic C Function Reference manual describes these
functions and the associated data structure tm.
tm_rd
Reads time and date values from the RTC.
tm_wr
Writes time and date values into the RTC.
The following points apply when using the RTC.
1. The AM/PM bit is 0 for AM, 1 for PM. The RTC also has a 24-hour
mode.
2. Set the year to 96 for 1996, 97 for 1997, and so on.
Constantly reading the RTC in a tight loop will result in a loss
of accuracy.
OP71.C
void delay( unsigned wDelay ){
for(;--wDelay;hitwd());
}
void main( void ){
unsigned wAddr;
for (;;)
for(wAddr=0x4140;wAddr<0x4148;++wAddr){
outport( wAddr,0x01 );
printf( "%04x%02x\n",wAddr,inport(0x4140) );
delay( 0x8000 );
outport( wAddr,0x00 );
}