MA31755 Datasheet, PDF (1/13 Pages) Dynex Semiconductor – 16-Bit Feedthrough Error Detection & Correction Unit EDAC

Replaces June 1999 version, DS3572-3.0
MA^M3^A1³7¹⁷5⁵5⁵
16-Bit Feedthrough Error Detection
& Correction Unit (EDAC)
DS3572-4.0 January 2000
The MA31755 is a 16 bit Error Detection and Correction
Unit intended for use in high integrity systems for monitoring
and correcting data values retrieved from memory. The EDAC
is placed in the data bus between the processor and the
memory to be protected. Extra check bits added at each
memory location are programmed transparently by the EDAC
during a processor write cycle. The entire checkword and data
combination is verified on read cycles. If any one bit in the
incoming data stream is at fault the EDAC can correct the fault
transparently, presenting the corrected 16-bit value to the
processor. An error in two bits can be detected but cannot be
corrected. Both the correctable and uncorrectable error
conditions are signalled to the system to allow the processor to
take action as required. Parity is passed through the device
unchanged as data bus bit 16.
Tri-statable bus transceivers with a high drive capability
are incorporated at the MD and CB busses which allows the
usual bus driver devices to be removed and reduces the
overall timing overhead imposed on the data bus. Although
designed primarily for MA31750 application, this part may be
used in almost any 16-bit processor system requiring high data
integrity.
FEATURES
s Fast Feedthrough (35ns Detect and Correct Cycle)
s 16-Bit Operation with 6 Check Bits
s Radiation Hard CMOS/SOS Technology
s Feedthrough Operation
s Error Corrected/Uncorrected Flags
s High Drive Capability on Memory Busses
8
VDD
8
VSS
MD[0:16]
CB[0:5]
MA31755
EDAC
PD[0:16]
CERRN
NCERRN
RDWN
XERRN
ENCOR
ENFLG
CS0
CS1N
CS2N
Figure 1: Chip Signals
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