Advance Information MC68HC908MR16/MC68HC908MR32 — Rev. 4.0
342 Analog-to-Digital Converter (ADC) MOTOROLA
Analog-to-Digital Converter (ADC)
19.2 Introduction
This section describes the 10-bit analog-to-digital converter (ADC).
19.3 Features
Features of the ADC module include:
10 channels with multiplexed input
Linear successive approximation
10-bit resolution, 8-bit accuracy
Single or continuous conversion
Conversion complete flag or conversion complete interrupt
Selectable ADC clock
Left or right justified result
Left justified sign data mode
High impedance buffered ADC input
19.4 Functional Description
Ten ADC channels are available for sampling external sources at pins
PTC1/ATD9:PTC0/ATD8 and PTB7/ATD7:PTB0/ATD0. To achieve the
best possible accuracy, these pins ar e implemented as input-only pins
when the analog-to-digital (A/D) feature is enabled. An analog
multiplexer allows the single ADC to select one of the 10 ADC channels
as ADC voltage IN (ADCVIN). ADCVIN is converted by the successive
approximation algorithm. When the co nversion is completed, the ADC
places the result in the ADC data register (ADRH and ADRL) and sets a
flag or generates an interrupt. See Figure 19-1.