User`s manual

XP8500
48 s Software Reference
The control program must input a series of 4-bit nibbles to read a con-
verted value from a selected XP8500s serial A/D converter chip or serial
EEPROM. Again, each nibble can carry only one bit of data or control
information. Each 4-bit nibble read back from an XP8500 during a
BUSRD0 cycle has the following format.
Bit 3: ENDCA/D end of conversion
1 = conversion cycle is not in process; OK to send/receive data
0 = conversion cycle is in process; do not send or receive data
Bit 2: SDAEEPROM serial data out
Bit 1: DOUTA/D serial data out
Bit 0: Board present
0 = selected board actually present
1 = selected board not found.
The standard Dynamic C library functions for the XP8500 will probably
suffice for all applications. Refer to the manufacturers data sheets for the
24C04 EEPROM and the TLC2543 A/D converter if there is a need to
write other routines using the BUSWR and BUSRD cycles.