5 I/O ADDRESS MAP & REGISTER FUNCTIONS
A base address register controls the beginning, or 'Base Address' of the I/O addresses
occupied by the control registers of the PCM-DAS08. In all, 16 addresses are
occupied (although only four have functions associated with them). The base address
assigned by CSS is stored in the CB.CBG file by InstaCal and read by the Universal
Library.
5.1 CONTROL REGISTERS
After CSS has been installed and a base address established, the PCM-DAS08 can be
controlled by writing to and reading from the control registers. While it is possible to
write your own control routines, routines have been written and are available in the
Universal Library for DOS and Windows programming languages.
5.2 REGISTER PROGRAMMING SUPPORT
While the complete register map is explained here, only very limited support for
assembly language or direct register programming is available. Register-level
programming should only be attempted by experienced programmers. We support the
use of the PCM-DAS08 through high level languages using Universal Library and the
example programs provided.
5.3 CONTROL REGISTERS
BASE + 0 - A/D LSB Data Register
Any write to this register will trigger an A/D conversion. This is a good method of
starting conversions from software or time of day clock control.
A/D Data can be read from this address and combined with data read from Base + 1 to
form a 12 bit A/D data word.
A/D0
A/D1
A/D2
A/D3
A/D4
A/D5
A/D6
A/D7
0
1
2
3
4
5
6
7
7