MAXIM MAXQ612 User Manual

19-5459; Rev 3; 11/11

ERRATA SHEET

MAXQ612

__________________________________________________________ Revision B1 Errata

The errata listed below describe situations where MAXQ612 revision B1 components perform differently
than expected or dif ferently than described in t he data sheet. Maxim Integrated Products, Inc. , intends t o
correct these errata when the opportunity to redesign the product presents itself.

This errata sheet only applies t o MAXQ612 revision B1 component s. Rev ision B1 c omponents are branded
on the topside of the package with a six-digit code in the form yywwB1, where yy and ww are two-digit
numbers representing t he year and wor k week of manufact ure, respectively . To obtain an errata sheet on
another MAXQ612 die revision, visit our webs ite at

1) WATCHDOG TIMER RESET LOCKS THE IC IN RESET
Description:

When the i nter nal oscill ator (PLL) i s used i n div i de-by-4 mode as system cl ock , the watchdog t i m er reset
locks the IC in reset. This requires a power cycle to recover .

Workaround:

Prevent watchdog tim er r esets by regular monitoring of the watchdog or by using the watchdog interrupt
to switch the system cl oc k away from internal oscillator (PLL).

www.maxim-ic.com/errata.

2) FLASH PROGRAM/ERASE OPERATIONS FAIL IN CLOCK-DIVIDED MODE
Description:

Flash word programming and page erase operations do not c om plete successfully when inv oked with
clock divide-by-2, divide-by-4, or divide-by-8 modes active.

Workaround:

When using the fl ash controller directly, write and erase func tions exercised through the FCNTL and
FDATA regi sters must be performed with a nondiv ided system mode setting (see the CKCN r egister
description). In addition, the following utility ROM function calls access the FCNTL and F DA TA r egisters
and have t he same requir ement pri or to being cal led: UROM_flashWrite, UROM_flashErasePage, and
UROM_flashEraseAll. T he system clock m ust be set to divide-by-1 mode befor e calling any of t hese
routines.

___________________________________Maxim Integrated Products 1

MAXQ612
REV B1 ERRATA

3) SYSTEM CODE IS INADVERTENTLY ERASED
Description:

When user loader and user application code is loaded in upper f lash memory (with address greater than
0x7FFF) with memory pr otection enabled, the system code is inadvertently erased.

Workaround:

Prevent using memor y prot ec tion capability or by making sure the code with t he lowest m em or y
privilege star ts below address 0x8000.

4) MEMORY PROTECTION FAULT ASSERTED
Description:

When entering debug mode in upper memory (IP > 0x 7FFF, SC_UPA = 1) the debug engine inc or r ec tly
drops the privi lege level to the lowest state. I f the area of mem ory being debugged requires a higher
privilege i n or der to be ac c essed, a memor y fault is generat ed upon r eturn from the debug code.

Workaround:

Avoid use of memory prot ection ( or ) av oid debug in the upper memory (or) by allowing only UAPP c ode
in the upper memory.

5) PUSH INSTRUCTION CAUSES CODE EXECUTION ERROR WHEN FOLLOWED BY READ OF
CERTAIN REGISTERS, OR IF THE MOD[1:0] BITS HAVE BEEN CHANGED FROM THEIR
DEFAULT VALUES

Description:

A PUSH instruction, followed immediately by an instruction reading the following register:
I2CBUF causes a code execution error. In addition, changing t he MOD[1:0] bits (APC[2:0]) fr om their

default value c an cause the device to operate incorrectly any time a PUSH instruction is followed by any
instruction which reads the active accumulat or .

Workaround:

The workaround is dependent on whether the programming language is C or assembly.
C code:

1. IAR Embedded Workbenc h: Code com piled by IAR Embedded Workbench versions 2.12 and earlier
is not affected by this erratum. Versions after 2.12 m ust add the f ollowing line at the beginning of any
function that accesses the peripherals menti oned above:

asm (“NOP”)

2. Rowley CrossWorks: Code com piled by Rowley CrossWorks versi ons 2.0 and ear lier is not affected
by this erratum. Versions after 2.0 must add the following li ne at the beginning of any function t hat
accesses the peripher als mentioned above:

__Insert_Opcode(0xDA3A)
Note that the line is preceded by two underscore characters.

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19-5459; Rev 3; 11/11