Motorola MPC533 Reference Manual page 476

Analog Subsystem
The result word table is read/write accessible by software. During normal operation,
application software only needs to read the result table. Write operations to the table may
occur during test or debug breakpoint operation. When locations in the CCW table are not
used by an application, software could use the corresponding locations in the result word
table as scratch pad RAM, remembering that only 10 bits are implemented. The result
alignment is only implemented for software read operations. Since write operations are not
the normal use for the result registers, only one write data format is supported, which is
right justified data.
Some write operations, like bit manipulation, may not operate
as expected because the hardware cannot access a true 16-bit
value.
13.4 Analog Subsystem
This section describes the QADC64E analog subsystem, which includes the front-end
analog multiplexer and analog-to-digital converter.
13.4.1 Analog-to-Digital Converter Operation
The analog subsystem consists of the path from the input signals to the A/D converter
block. Signals from the queue control logic are fed to the multiplexer and state machine.
The end of convert (EOC) signal and the successive-approximation register (SAR) are the
result of the conversion. Figure 13-18 shows a block diagram of the QADC64E analog
subsystem.
13-32
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
NOTE
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