TABLE VII DP8402A DP8403 Diagnostic Function

DB BYTE

DB OUTPUT

CB

ERROR FLAGS

EDAC FUNCTION

CONTROL

DATA IO

CONTROL

LATCH

CHECK IO

CONTROL

ERR

MERR

S1

S0

OEBn

LEDBO

OECB

Read

flag

H

L

Input correct

HX

Input correct

HH

H

data word

check bits

Latch input check

Input

Input

word while data

L

H

diagnostic

H

L

check bits

H

Enabled

input latch remains

data word

latched

transparent

Latch diagnostic

Input

Output latched

L

data word into

L

H

diagnostic

H

H

check bits

Enabled

output latch

data word

Hi-Z

H

Latch diagnostic

Input

Output

data word into

H

H

diagnostic

H

H

syndrome

L

Enabled

input latch

data word

bits

latched

Hi-Z

H

Output

Output diagnostic

Output

syndrome

L

data word

H

H

diagnostic

L

H

bits

Enabled

syndrome bits

data word

Hi-Z

H

Output corrected

Output

Output

diagnostic data

HH

corrected

LL

syndrome

L

Enabled

word

output

diagnostic

bits

syndrome bits

data word

Hi-Z

H

Diagnostic data is a data word with an error in one bit location except when testing the MERR error flag In this case the diagnostic data word will contain errors in

two bit locations

TABLE VIII DP8404 DP8405 Diagnostic Function

EDAC FUNCTION

CONTROL

DATA IO

DB CONTROL

CHECK IO

DB CONTROL

ERROR FLAGS

S1

S0

OEDB

OECB

ERR

MERR

Read

flag

H

L

Input correct

H

Input correct

HH

H

data word

check bits

Latch input check

Input

Input

bits while data

L

H

diagnostic

H

check bits

H

Enabled

input latch remains

data word

latched

transparent

Input

Output input

L

H

diagnostic

H

Output input

L

Enabled

check bits

data word

check bits

Latch diagnostic

Input

Output

L

data into

H

H

diagnostic

H

syndrome bits

Enabled

input latch

data word

Hi-Z

H

latched

Output corrected

Output corrected

Output

L

diagnostic

H

H

diagnostic

L

syndrome bits

Enabled

data word

data word

Hi-Z

H

Diagnostic data is a data word with an error in one bit location except when testing the MERR error flag In this case the diagnostic data word will contain errors in

two bit locations

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