MC68376BGMAB20 Freescale Semiconductor, MC68376BGMAB20 Datasheet - Page 192

• Manufacturer Part Number: MC68376BGMAB20
• Description: IC MCU 32BIT 8K ROM 160-QFP
• Manufacturer: Freescale Semiconductor
• Series: M683xxr

Specifications of MC68376BGMAB20

• Core Processor: CPU32
• Core Size: 32-Bit
• Speed: 20MHz
• Connectivity: CAN, EBI/EMI, SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 18
• Program Memory Type: ROMless
• Ram Size: 7.5K x 8
• Voltage - Supply (vcc/vdd): 4.75 V ~ 5.25 V
• Data Converters: A/D 16x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 160-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -

8.9 External Multiplexing Operation
8-10
MOTOROLA
External multiplexers concentrate a number of analog signals onto a few inputs to the
analog converter. This is helpful in applications that need to convert more analog sig-
nals than the A/D converter can normally provide. External multiplexing also puts the
multiplexer closer to the signal source. This minimizes the number of analog signals
that need to be shielded due to the close proximity of noisy, high speed digital signals
near the MCU.
The QADC can use from one to four external multiplexers to expand the number of
analog signals that may be converted. Up to 32 analog channels can be converted
through external multiplexer selection. The externally multiplexed channels are auto-
matically selected from the channel field of the conversion command word (CCW) ta-
ble, the same as internally multiplexed channels.
All of the automatic queue features are available for externally and internally multi-
plexed channels. The software selects externally multiplexed mode by setting the
MUX bit in QACR0.
Figure 8-3 shows the maximum configuration of four external multiplexers connected
to the QADC. The external multiplexers select one of eight analog inputs and connect
it to one analog output, which becomes an input to the QADC. The QADC provides
three multiplexed address signals (MA[2:0]), to select one of eight inputs. These
outputs are connected to all four multiplexers. The analog output of each multiplexer
is each connected to one of four separate QADC inputs — ANw, ANx, ANy, and ANz.
QUEUED ANALOG-TO-DIGITAL CONVERTER MODULE
USER’S MANUAL
MC68336/376