AN1921 Motorola / Freescale Semiconductor, AN1921 Datasheet - Page 8

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

Interfacing to Serial Devices Using the SPI Port
8
Figure 5. View of Prototype Board Showing the Motorola Absolute Barometric Sensor
The TI TLC2543 SPI device is interfaced to the DSP’s SPI0 port by means of the EVM’s J1 header
pins. The TLC2543 is a MUXed 11-channel, 12-bit analog-to-digital converter. Control of the
TLC2543 chip is performed when the application code sends a command word to it. A description of
the TLC2543 command word appears in Appendix 2.
The C code is written using Motorola’s Embedded SDK’s SPI library and the BSP library. Using a
prototype board (see
power, reference voltages and ground to the ADC. See
placed between J1’s 1,3,5, and 7 pins and the CLKIN, DATAIN, DATAOUT, and CS on the TLC2543
(see
The C code procedure (InitTLC2453.c) is used to establish and test the interface between the
SPI0 and the ADC.
SPI0.
Figure 6
Table 3: Connections between SPI0 (J1) EVM Header and TLC2543 Chip
and
Table
Figure
Code Example 2
3).
Interface Examples Using the Embedded SDK
J1 Header Signal
5) to support the TLC2543, all required connections are made to provide
MISO1/PC0
MOSI1/PC1
SCK1/PC2
SS1/PC3
and TLC5423 ADC
, InitTLC2543.c, shows operation of TLC2543 from
I/O CLOCK (18)
TLC2543 lines
DATAOUT (16)
DATA IN (17)
CS (15)
Figure 6
for a schematic. Jumper wires are