Functional Description
Table 26-1. ROM Exception Vectors
Address
Exception
Content
20000h
Reset
Branch to the Public ROM Code startup
20004h
Undefined
PC = 4030CE04h
20008h
SWI
PC = 4030CE08h
2000Ch
Pre-fetch abort
PC = 4030CE0Ch
20010h
Data abort
PC = 4030CE10h
20014h
Unused
PC = 4030CE14h
20018h
IRQ
PC = 4030CE18h
2001Ch
FIQ
PC = 4030CE1Ch
Public ROM Code CRC
The Public ROM Code CRC is calculated as 32 bit CRC code (CRC-32-IEEE 802.3) for the address range
20000h–2BFFFh. The four bytes CRC code is stored at location 20020h.
Dead Loops
Built-in dead loops are used for different purposes as shown in below
. All dead loops are
branch instructions coded in ARM mode. The fixed location of these dead loops facilitates debugging and
testing. The first seven dead loops are default exception handlers linked with RAM exception vectors. The
dead loops might be called directly from the user code. However there exists a special function which can
be called from ROM Code in order to execute a dead loop. The function is an assembly code in ARM
mode which takes the dead loop address from R0 register. The main purpose of the function is to go in a
dead loop until the watchdog expires and resets the device. The function is located at address 200C0h. In
addition the function clears global cold reset status upon issuing the global SW reset.
Table 26-2. Dead Loops
Address
Purpose
20080h
Undefined exception default handler
20084h
SWI exception default handler
20088h
Pre-fetch abort exception default handler
2008Ch
Data abort exception default handler
20090h
Unused exception default handler
20094h
IRQ exception default handler
20098h
FIQ exception default handler
2009Ch
Validation tests PASS
200A0h
Validation tests FAIL
200A4h
Reserved
200A8h
Image not executed or returned.
200ACh
Reserved
200B0h
Reserved
200B4h
Reserved
200B8h
Reserved
200BCh
Reserved
Code
This space is used to hold code and constant data.
Public ROM Code Version
The ROM Code version consists of two decimal numbers: major and minor. It can be used to identify the
ROM Code release version in a given IC (e.g., useful to identify an IC version). The ROM Code version is
a 32bits hexadecimal value located at address 2BFFCh.
4099
SPRUH73H – October 2011 – Revised April 2013
Initialization
Copyright © 2011–2013, Texas Instruments Incorporated