1024-Bit, 1-Wire EEPROM

for Automotive Applications

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9

BUS MASTER Tx MEMORY

FUNCTION COMMAND

BUS MASTER Tx

TA1 (T7:T0), TA2 (T15:T8)

BUS MASTER Rx

TA1 (T7:T0), TA2 (T15:T8),

AND E/S BYTE

BUS MASTER Rx

DATA BYTE FROM

SCRATCHPAD

MASTER Tx DATA BYTE

TO SCRATCHPAD

APPLIES ONLY

IF THE MEMORY

AREA IS NOT

PROTECTED.

IF WRITE PROTECTED,

THE DS2431-A1

COPIES THE DATE

BYTE FROM THE

TARGET ADDRESS

INTO THE SP.

IF IN EPROM MODE,

THE DS2431-A1

LOADS THE BITWISE

LOGICAL AND,

THE TRANSMITTED

BYTE, AND THE

DATA BYTE FROM

THE TARGETED

ADDRESS INTO

THE SP.

BUS MASTER

Rx "1"s

DS2431-A1

INCREMENTS

E2:E0

PF = 0

DS2431-A1 SETS

SETS PF = 1

CLEARS AA = 0

SETS E2:E0 = T2:T0

0Fh

WRITE SCRATCHPAD?

N

Y

N

Y

N

Y

Y

Y

N

N

MASTER Tx RESET?

E2:E0 = 7?

T2:T0 = 0?

MASTER Tx RESET?

DS2431-A1 SETS

SCRATCHPAD

BYTE COUNTER = T2:T0

AAh

READ SCRATCHPAD?

N

Y

DS2431-A1 Tx CRC-16 OF

COMMAND, ADDRESS,

DATA BYTES AS THEY

WERE SENT BY THE BUS

MASTER

BUS MASTER

Rx "1"s

Y

N

MASTER Tx RESET?

BUS MASTER Rx CRC-16

OF COMMAND, ADDRESS,

E/S BYTE, DATA BYTES

AS SENT BY THE DS2431-A1

Y

N

MASTER Tx RESET?

Y

BYTE COUNTER

= E2:E0?

FROM ROM FUNCTIONS

FLOW CHART (FIGURE 9)

TO ROM FUNCTIONS

FLOW CHART (FIGURE 9)

DS2431-A1

INCREMENTS

BYTE COUNTER

N

TO FIGURE 7

2ND PART

TO FIGURE 7

2ND PART

Figure 7. Memory Function Flow Chart