User`s manual
UPS25  32  RTD Embedded Technologies, Inc 
 BA+1 Status register   (Read) 
The UPS25 status register gives you access to monitor the state of your board. 
This register is reset to all zeroes after power-up and reset of your CPU. 
Bit 0    0  Main supply voltage low / UPS25 in backup state 
    1  Main power OK, charging can take place 
Bit 1    0  Battery voltage low 
    1  Battery voltage still OK 
Bit 2    Charger status LED 
  Bit 3    Charger temperature LED 
      0  Battery temperature out of limits, no charging can take place 
      1  Battery temperature OK, charging can take place 
 BA+1 Status register   (Write) 
  Clear the host interrupt register. Must be performed for a new interrupt to be 
  possible to take place. 
 Programming the UPS25 
This  section  gives  you  some  general  information  about  programming  the  UPS25 
board. It then walks you through the major programming functions of  the UPS25. 
This will help you use the example program that is included with the board. All of the 
program descriptions use decimal values unless otherwise specified. 
The UPS25  is  programmed by  writing  to  the correct  board I/O  port  addresses. 
These I/O ports were described in the previous section of this chapter. The following 
example shows how to perform an 8-bit write to I/O port addresses using "C"-syntax 
and assembly code: 
          Write: 
"C"-syntax        outp(address,data); 
Assembly        mov dx,address 
          mov ax,data 
          out dx,ax 










