2.7 A/D Conversion This section explains how to perform A/D conversions. The A/D conversion
can be performed by software trigger by pacer trigger. At the end of the
A/D conversion, it is possible to transfer data by polling and interrupt
before using the A/D conversion function; users should notice the following
issues:
z A/D data register, BASE+4/BASE+5, stores the A/D conversion data (sec. 2.4.2)
z A/D gain control register, BASE+9, select gain (sec. 2.4.6)
(
sec. 2.4.7
)
z A/D multiplex control register, BASE+A, select analog input
z A/D mode control register, BASE+B, select trigger type and transfer
type (sec. 2.4.8)
z A/D software trigger control register, BASE+C (sec. 2.4.9)
The block diagram is given below:
Base+C
OME-A-8111
Base+B
Base+A Base+9 Trigger
Logic
CPU Transfer
Logic
Memory
Buffer
12 bits
A/D
Gain
Control
7 to 0
Multi-
plexer
CN1
OME-A-8111 Hardware Manual (ver.1.1, Jul/2003) 21