Analog Devices Errata812 f2 Datasheet

MicroConverter®, Multi-Channel 12-bit

a

Errata Sheet

A. This Errata sheet represents the known bugs, anomalies and work-arounds for the ADuC812 MicroConverter.

B. The Errata listed, apply to all ADuC812 packaged material branded as follows :

(Production Material)

ADUC812BS
Date Stamp AD Logo C
Lot Number

(Note : The indentifier ‘C’ after the ADLogo on the second line of the brand)

C. Errata Sheets referring to previous silicon revisions are available on our web-site at

http://www.analog.com/microconverter/erratasheets.html

ADC with Embedded FLASH MCU

ADuC812

D. Because of silicon revisions and improved work-arounds, this Errata Sheet will be updated periodically. Please

find the latest Errata Sheet listed on the World Wide Web at :

http://www.analog.com/microconverter/erratasheets.html

E. Analog Devices Inc. is committed, through future silicon revisions to continuously improve silicon functionality.

Analog Devices Inc. will use its best endeavors to ensure that these future silicon revisions remain compatible with
your present software/systems that implement the recommended work-arounds outlined in this document.

REV. F.2 FEB/02

Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.

® MicroConverter is a Trademark of Analog Devices, Inc.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] World Wide Web Site: http://www.analog.com
Fax: [phone] Analog Devices, Inc., 2000

ADuC812

812_S01. ADC FUNCTION - ADC CONVERSION IN DMA MODE :

Background: The ADC can be triggered by 1 of 4 trigger events in Normal and DMA

operating modes, namely: Single Software Conversion, Continuous
Software Conversions, External Pin Triggered Conversions and Timer2
triggered Conversions. DMA mode is initiated by setting the DMA bit in
the ADCCON2 SFR and the DMA controller proceeds starting from the
external data memory address indicated by the DMA address SFRs
DMAL/H/P. Once a DMA conversion sequence is complete, both the
DMA bit and the bit controlling the conversion mode are reset by the
DMA controller.

Issue A: DMA operation will not execute when triggered from Timer2 driven

conversions unless when configuring the ADC, ADCCON2 is written
prior to ADCCON1.

Work-Around A: For Timer2 triggered DMA conversions, ensure that the correct

configuration sequence is used for the ADC, i.e. configure ADCCON2
then ADCCON1.

Issue B: DMA operation will not execute when triggered from Timer2 driven

conversions unless DMA Address (DMAL/H/P) is initially set to
000000H.

Errata Sheet

Work-Around B: For Timer2 triggered DMA conversions, ensure that the DMA start

address is set to 000000H.

Related Issues : None.

812_S02. UART FUNCTION - MULTIPROCESSOR COMMUNICATIONS MODE :

Background: UART Modes 2 and 3 (programmed via SCON) have a special provision

for multiprocessor communications. In these modes, nine data bits are
received and the ninth bit goes into RB8. In this mode the port can be
programmed so that when the stop bit is received, the serial port interrupt
is activated only if RB8(SCON) = 1. This feature is enabled by setting the
SM2 bit in SCON.

Issue: With SM2 set, the serial port interrupt is set each time a stop bit is

received, regardless of the state of the RB8 bit.

Work-Around : Implement a software polling scheme in the Serial Port ISR so that the

state of the RB8 bit is checked on entering the ISR. If RB8 is ‘0’ then a
‘RETI’ is executed to exit the ISR immediately, and only if RB8 is set will
the ISR function be executed.

Related Issues : None.

REV. F.2 FEB/02

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