CDB5378 datasheet(27/72 Pages) CIRRUS

27 / 72 page

CDB5378

DS639DB3

Many connections to the C8051F320 microcontroller are inactive by default, but are provided for conve-

nience during custom reprogramming. Listed below are the default active connections to the microcon-

troller and how they are used.

2.3.4.1

SPI Interface

The microcontroller SPI interface communicates with the CS5378 digital filter to write/read configuration

information and collect conversion data from the SPI port. Detailed information about interfacing to the

digital filter SPI port can be found in the CS5378 data sheet.

2.3.4.2

USB Interface

The microcontroller USB interface communicates with the PC evaluation software to receive configuration

commands and return collected conversion data. The USB interface uses the Silicon Laboratories API

and Windows drivers, which are available free from the internet (http://www.silabs.com).

2.3.4.3

Reset Source

By default, the C8051F320 microcontroller receives its reset signal from the RESET_PBz push button.

2.3.4.4

Clock Source

By default, the C8051F320 microcontroller uses an internally generated 12 MHz clock for compatibility

with USB standards.

2.3.4.5

Timebreak Signal

By default, the C8051F320 microcontroller sends the TIMEB_MC signal to the digital filter for the first col-

lected sample of a data record. By default, 100 initial samples are skipped during data collection to ensure

the CS5378 digital filters are fully settled, and the timebreak signal is automatically set for the first “real”

collected sample.

2.3.4.6

C2 Debug Interface

Through the PC evaluation software, the microcontroller default firmware can be automatically flashed to

the latest version without connecting an external programmer. To flash custom firmware, software tools

and an inexpensive hardware programmer (DEBUGADPTR1-USB) that connects to the C2 Debug Inter-

face on CDB5378 are available from Silicon Laboratories.

2.3.5

RS-485 Telemetry

By default, CDB5378 communicates with the PC evaluation software through the microcontroller USB

port. Additional hardware is designed onto CDB5378 to use the microcontroller I2C port as a low-level

local telemetry, but it is provided for custom programming convenience only and is not directly supported

by the CDB5378 PC evaluation software or microcontroller firmware.

CDB5378 Datasheet(PDF) 27 Page - Cirrus Logic