MC68HC912B32MFU8 MOTOROLA [Motorola, Inc], MC68HC912B32MFU8 Datasheet - Page 108

• Manufacturer Part Number: MC68HC912B32MFU8
• Description: 16-Bit Microcontroller
• Manufacturer: MOTOROLA [Motorola, Inc]

15 Analog-To-Digital Converter
15.1 Functional Description
15.2 ATD Registers
ATDCTL0 — Reserved
108
MOTOROLA
RESET:
The ATD is an 8-channel, 8-bit, multiplexed-input successive-approximation analog-to-digital converter,
accurate to 1 least significant bit (LSB). It does not require external sample and hold circuits because
of the type of charge redistribution technique used. The ATD converter timing is synchronized to the
system P clock. The ATD module consists of a 16-word (32-byte) memory-mapped control register
block used for control, testing and configuration.
A single conversion sequence consists of four or eight conversions, depending on the state of the select
8 channel mode (S8CM) bit when ATDCTL5 is written. There are eight basic conversion modes. In the
non-scan modes, the SCF bit is set after the sequence of four or eight conversions has been performed
and the ATD module halts. In the scan modes, the SCF bit is set after the first sequence of four or eight
conversions has been performed, and the ATD module continues to restart the sequence. In both
modes, the CCF bit associated with each register is set when that register is loaded with the appropriate
conversion result. That flag is cleared automatically when that result register is read. The conversions
are started by writing to the control registers.
Bit 7
0
0
Figure 26 Analog-to-Digital Converter Block Diagram
6
0
0
AND COMPARATOR
RC DAC ARRAY
5
0
0
ATD 0
ATD 1
ATD 2
ATD 3
ATD 4
ATD 5
ATD 6
ATD 7
SAR
INTERNAL BUS
4
0
0
SELECT/PRESCALE
3
0
0
SAMPLE BUFFER AMP
DATA INPUT REGISTER
CLOCK
ANALOG MUX
PORT AD
2
0
0
AND
1
0
0
V
V
V
V
RH
RL
DDA
SSA
HC12 ATD BLOCK
MC68HC912B32TS/D
AN7/PAD7
AN6/PAD6
AN5/PAD5
AN4/PAD4
AN3/PAD3
AN2/PAD2
AN1/PAD1
AN0/PAD0
REFERENCE
SUPPLY
Bit 0
MC68HC912B32
0
0
$0060