1024-Bit, 1-Wire EEPROM
BUS MASTER Tx MEMORY
FUNCTION COMMAND
FROM ROM FUNCTIONS
FLOWCHART (FIGURE 9)
0Fh
AAh
TO FIGURE 7b
N
N
WRITE SCRATCHPAD?
READ SCRATCHPAD?
DS2431
Y
Y
BUS MASTER Tx
TA1 (T[7:0]), TA2 (T[15:8])
BUS MASTER Rx
TA1 (T[7:0]), TA2 (T[15:8]),
AND E/S BYTE
DS2431
SETS PF = 1
CLEARS AA = 0
SETS E[2:0] = T[2:0]
DS2431 SETS
SCRATCHPAD
BYTE COUNTER = T[2:0]
MASTER Tx DATA BYTE
TO SCRATCHPAD
DS2431
INCREMENTS
BYTE COUNTER
BUS MASTER Rx
DATA BYTE FROM
SCRATCHPAD
APPLIES ONLY
IF THE MEMORY
AREA IS NOT
PROTECTED.
IF WRITE PROTECTED,
THE DS2431 COPIES
THE DATE BYTE FROM
THE TARGET ADDRESS
INTO THE SCRATCHPAD.
DS2431
INCREMENTS
E[2:0]
Y
MASTER Tx RESET?
N
Y
MASTER Tx RESET?
N
IF IN EPROM MODE,
THE DS2431 LOADS
THE BITWISE LOGICAL
AND OF THE TRANSMITTED
BYTE AND THE DATA
BYTE FROM THE TARGETED
ADDRESS INTO THE
N
E[2:0] = 7?
Y
N
BYTE COUNTER
= E[2:0]?
Y
SCRATCHPAD.
N
BUS MASTER Rx CRC-16
OF COMMAND, ADDRESS,
E/S BYTE, AND DATA BYTES
AS SENT BY THE DS2431
T[2:0] = 0?
Y
PF = 0
N
BUS MASTER
Rx "1"s
MASTER Tx RESET?
Y
DS2431 Tx CRC-16 OF
COMMAND, ADDRESS,
AND DATA BYTES AS THEY
WERE SENT BY THE BUS
MASTER
N
BUS MASTER
Rx "1"s
MASTER Tx RESET?
Y
FROM FIGURE 7b
TO ROM FUNCTIONS
FLOWCHART (FIGURE 9)
Figure 7a. Memory Function Flowchart
10 ______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
