Integrated Device Technology, Inc.

COMMERCIAL TEMPERATURE RANGES

AUGUST 1996

©1996 Integrated Device Technology, Inc.

11.7

DSC-2617/9

64-BIT FLOW-THRU

ERROR DETECTION

AND CORRECTION UNIT

The IDT logo is a registered trademark and Flow-thruEDC is a trademark of Integrated Device Technology Inc.

FEATURES:

• 64-bit wide Flow-thruEDC

™

• Separate System and Memory Data Input/Output Buses

• — Error Detect Time: 10ns

— Error Correct Time: 15ns

• Corrects all single bit errors; Detects all double bit errors

and some multiple bit errors

• Configurable 16-deep bus read/write FIFOs with flags

• Simultaneous check bit generation and correction of memory

data

• Supports partial word writes on byte boundaries

• Low noise output

• Sophisticated error diagnostics and error logging

• Parity generation on system data bus

• 208-pin Plastic Quad Flatpack

2617 drw 01

SD

CHK-BIT

LATCH

WRITE

BUFFER

16 WORDS BY

72

SD

LATCH

IN

MD

LATCH

OUT

READ BUFFER

16 WORDS BY

64

MD

LATCH

IN

SD

LATCH

OUT

ERROR

CORRECT

CHECK-BIT

COMPARATOR &

SYNDROME

GENERATOR &

ERROR

DETECTOR

SD

CHECK-BIT

GENERATOR

MD

CHECK-BIT

GENERATOR

B

Y

T

E

M

U

X

MD

CHK-BIT

LATCH

WRITE BACK PATH

DIAGNOSTIC

& STATUS

REGISTERS

PARITY

GENERATE &

PARITY CHECK

PARITY

SD0-63

ERR

MERR

MD0-63

M

U

X

M

U

X

M

U

X

P0-7

CBI0-7

CBSYN0-7

1

IDT49C466

IDT49C466A

SIMPLIFIED FUNCTIONAL BLOCK DIAGRAM

DESCRIPTION:

The IDT49C466/A 64-bit Flow-thruEDC is a high-speed

error detection and correction unit that ensures data integrity

in memory systems. The flow-thru architecture, with separate

system and memory data buses, is ideally suited for pipelined

memory systems.

Implementing

a

modified

Hamming

code,

the

IDT49C466/A corrects all single bit hard and soft errors, and

detects all double bit errors. The read/write FIFOs can store

up to sixteen words.

FIFO full and empty flags indicate

whether additional data can be written to or read from the

EDC.

Check bit generation for partial word writes on byte bound-

aries is supported on the IDT49C466/A.

Diagnostic features include a check bit register, syndrome

registers, a four bit error counter which logs up to 15 errors,

and an error data register which stores the complete error data

word. Parity can be generated and checked on the system

bus by the IDT49C466/A.