AN1921 Motorola / Freescale Semiconductor, AN1921 Datasheet - Page 24

• Manufacturer Part Number: AN1921
• Description: AN1921 General DSP568xx Interface Examples using the Embedded SDK
• Manufacturer: Motorola / Freescale Semiconductor

Integrating Devices With the EVM Board
Appendix B.
B.1 Operating Principles
24
The following data is taken from TI’s TLC2543 data sheet. It is included only to provide information
that the reader may need to understand the code described in this note.
The TLC2543 is a 12-bit switched-capacitor, successive approximation, ADC converter. Each device
has three control inputs (chip select (CS), the I/O clock and the address input (DATA INPUT)) and is
designed for communication with the serial port of a host processor or peripheral through a serial
3-state output.
The device has an on-chip 14-channel multiplexer that can select any of 11 inputs or any of three
internal self-test voltages. The sample-and-hold function is automatic. At the end-of-conversion
(EOC), output goes high to indicate that conversion is complete. A switched-capacitor design allows
low-error conversion over the full operating temperature
20- pin DIP version of the chip used in this note.
If the CS is high, the I/O CLOCK and DATA INPUT are disabled and DATA OUT is in a
high-impedance state. When the CS goes low, the conversion sequence begins by enabling the I/O
CLOCK and DATA INPUT and removes the DATA OUT from the high-impedance state.
The data input is 8 bits long and is primarily a command item exercising control over the features of
the chip. The following table describes the fields of the data input.
Figure B-1. TLC2543 DIP Version Pin-Outs
Interface Examples Using the Embedded SDK
TI’s TLC2543
AIN0
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AIN8
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
EOC
I/O CLOCK
DATA INPUT
DATA OUT
CS
REF+
REF-
AIN10
AIN9
CC
range.Figure B-1
shows the pin-outs of the