MC68HC05V12 Datasheet, PDF (130/246 Pages) Freescale Semiconductor, Inc – HCMOS Microcontreller Unit

Freescale Semiconductor, Inc.
Analog-to-Digital (A/D) Converter
13.5 A/D Status and Control Register
This subsection describes the function of the A/D status and control
register.
Address: $001E
Bit 7
6
5
4
3
2
1
Bit 0
Read: COCO
ADRC ADON CH4
CH3
CH2
CH1
CH0
Write:
Reset: 0
0
0
0
0
0
0
0
= Unimplemented
Figure 13-1. A/D Status and Control Register (ADSCR)
COCO — Conversions Complete Bit
This read-only status bit is set when a conversion is completed,
indicating that the A/D data register contains valid results. This bit is
cleared whenever the A/D status and control register is written and a
new conversion automatically started, or whenever the A/D data
register is read. Once a conversion has been started by writing to the
A/D status and control register, conversions of the selected channel
will continue every 32 cycles until the A/D status and control register
is written again. In this continuous conversion mode, the A/D data
register will be filled with new data, and the COCO bit set, every 32
cycles. Data from the previous conversion will be overwritten
regardless of the state of the COCO bit prior to writing.
ADRC — RC Oscillator Control Bit
When ADRC is set, the A/D section runs on the internal RC oscillator
instead of the CPU clock. The RC oscillator requires a time, t_RCON, to
stabilize, and results can be inaccurate during this time.
ADON — A/D On Bit
When the A/D is turned on (ADON = 1), it requires a time, t_ADON, for
the current sources to stabilize, and results can be inaccurate during
this time. This bit turns on the charge pump.
Technical Data
Analog-to-Digital (A/D) Converter
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MC68HC05V12 — Rev. 2.0