MC68HC11KW1 Datasheet, PDF (200/238 Pages) Motorola, Inc – High-density complementary metal oxide semiconductor HCMOS) microcontroller unit

10.3.1 4-conversion, single scan
Whichever port E or G pin is selected, the first result will be stored in the ADR5 result register and
the fourth result will be stored in the ADR8 register. After the fourth conversion is complete all
conversion activity is halted until a new conversion command is written to the ADCTL control
register.
10.3.2 4-conversion, continuous scan
Conversions continue to be performed on the selected channel with the fifth conversion being
stored in the ADR5 register (overwriting the first conversion result), the sixth conversion overwrites
ADR6, the seventh overwrites ADR7, and so on continuously. Using this variation, the data in any
result register is at most four conversion times old.
10.3.3 8-conversion, single scan
The result of the first conversion will be placed in result register ADR1, while the result of the
eighth conversion will be placed in result register ADR8. After the eighth conversion is complete
all conversion activity is halted until a new conversion command is written to the ADCTL control
register.
10.3.4 8-conversion, continuous scan
10
Conversions continue to be performed on the selected channel with the ninth conversion being
stored in the ADR1 register (overwriting the first conversion result), the tenth conversion
overwrites ADR2, the eleventh overwrites ADR3, and so on continuously. Using this variation, the
data in any result register is at most eight conversion times old.
10.4
Multiple channel operation
Multiple channel operation is selected by writing a one to the MULT bit in the A/D control and
status register (ADCTL). This mode has four variations, which can be selected using the CONV8
and SCAN bits in the ADCTL register. In the first two variations, the CONV8 bit is clear and a group
of four channels is selected. In this multiple channel mode, the group of channels selected
depends only on the two most significant bits of the channel address (CD and CC). In the second
two variations, the CONV8 bit is set and a group of eight channels is selected, depending on the
state of the CD bit. The state of the SCAN bit determines whether continuous or single scanning
is selected. Refer to Table 10-1.
10-4
ANALOG-TO-DIGITAL CONVERTER
MC68HC11KW1