Rev. 0.9 10/16
Copyright © 2016 by Silicon Laboratories
AN543
Silicon Laboratories Confidential. Information contained herein is covered under non-disclosure agreement (NDA).
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1. Introduction
This document provides an overview of the programming requirements for the Si475x-A10/A20/A30/A40/A55 and
Si475xC-A55 AM/FM receiver. The hardware control interface and software commands are detailed along with
several examples of the required steps to configure the device for various modes of operation. Table 1 provides a
programming guide cross-reference for each Si475x part released by Silicon Labs to date. This programming guide
focuses on the Si475x/5xC-A55 release; however, features, properties, ranges, and defaults that differ from the
Si475x-A10 to Si475x-A40 are noted as well. Refer to previous versions of this document for earlier firmware
revisions.
2. Overview
This devices in this product family are programmed using commands and responses. To perform an action, the
system controller writes a command byte and associated arguments, which cause the device to execute the given
command. The device will, in turn, provide a response depending on the type of command that was sent.
The device has a slave control interface that allows the system controller to send commands to and receive
responses from the device using 2-wire mode (I
2
C compatible).
3. Terminology
CTS
—Clear to send
STC
—Seek/Tune Complete
NVM
—Non-volatile internal device memory
Device
—Refers to the AM/FM Receiver
System Controller
—Refers to the system microcontroller
CMD
—Command byte
ARGn
—Argument byte (n = 1 to 7)
STATUS
—Status byte
RESPn
—Response byte (n = 1 to 15)
Table 1. Si475x Firmware Revisions
Part #
Part Revision
FMRX Component
AMRX Component
Si475x-A10
1.0
3.2.3
3.2.3
Si475x-A20
2.0
8.0.8
7.0.5
Si475x-A30
3.0
10.0.8
9.0.6
Si475x-A40
4.0
13.0.11
12.0.10
Si475x-A55
5.5
15.0.2
14.0.1
Si475xC-A55
5.5
15.0.2
14.0.1
