ATAM893S Datasheet, PDF (1/3 Pages) ATMEL Corporation – MARC4 4-bit Microcontrollers

DI Errata
• ATAM893S
• ATAM894P
• ATAR092P
• ATAR892P
• ATAR090H
• ATAR890H
• ATAR080F
• ATA6020N
• ATAR510F
• ATAR862N3/N4/N8
The latest product enhancement (PCN HC030703 DI enhancement) introduced to all
MARC4 products during 2003, leads, under some conditions, to an unforeseen and
unwanted behavior. The circuit may not process interrupts correctly. All above men-
tioned MARC4 products are affected.
Description
If a DI command is immediately followed by a CALL or SCALL command and an inter-
rupt meets this DI command, this interrupt is kept in the interrupt active register
permanently despite a correct RTI execution. Even if the EI command in the inter-
rupted program has been executed, this bit in the interrupt active register stays set
and disables the execution of any interrupt of the same or lower priority. Only an inter-
rupt with a higher priority or a reset is able to solve this blocking status.
If the command following the DI is a NOP, the interrupt active register usually is
cleared correctly after an RTI and executing interrupts then continues normally.
MARC4 4-bit
Microcontrollers
ATAM893S
ATAM894P
ATAR092/892P
ATAR090/890H
ATAR080F
ATA6020N
ATAR510F
ATAR862N3/4/8
Errata Sheet
Rev. 4813A–4BMCU–06/04