MC9S12GRMV1 Datasheet, PDF (572/1292 Pages) Freescale Semiconductor, Inc – MC9S12G Family Reference Manual and Data Sheet

Digital Analog Converter (DAC_8B5V)
Table 17-2. Terminology (continued)
Term
VRH
FVR
SSC
High Reference Voltage
Full Voltage Range
Special Single Chip
Meaning
17.2 Introduction
The DAC_8B5V module is a digital to analog converter. The converter works with a resolution of 8 bit and
generates an output voltage between VRL and VRH.
The module consists of configuration registers and two analog functional units, a DAC resistor network
and an operational amplifier.
The configuration registers provide all required control bits for the DAC resistor network and for the
operational amplifier.
The DAC resistor network generates the desired analog output voltage. The unbuffered voltage from the
DAC resistor network output can be routed to the external DACU pin. When enabled, the buffered voltage
from the operational amplifier output is available on the external AMP pin.
The operational amplifier is also stand alone usable.
Figure 17-1 shows the block diagram of the DAC_8B5V module.
17.2.1 Features
The DAC_8B5V module includes these distinctive features:
• 1 digital-analog converter channel with:
— 8 bit resolution
— full and reduced output voltage range
— buffered or unbuffered analog output voltage usable
• operational amplifier stand alone usable
17.2.2 Modes of Operation
The DAC_8B5V module behaves as follows in the system power modes:
1. CPU run mode
The functionality of the DAC_8B5V module is available.
2. CPU stop mode
Independent from the mode settings, the operational amplifier is disabled, switch S1 and S2 are
open.
MC9S12G Family Reference Manual, Rev.1.23
574
Freescale Semiconductor