DS1921G_11 MAXIM [Maxim Integrated Products], DS1921G_11 Datasheet - Page 22

• Manufacturer Part Number: DS1921G_11
• Description: Logs Up to 2048 Consecutive Temperature Thermochron iButton
• Manufacturer: MAXIM [Maxim Integrated Products]

Thermochron iButton
Figure 10a. Memory/Control Function Flowchart
22
SCRATCHPAD
INCREMENTS
DS1921G
OFFSET
______________________________________________________________________________________
N
Y
Y
CONTROL FUNCTION COMMAND
SCRATCHPAD OFFSET = [T4:T0]
COMMAND, ADDRESS, DATA
TO SCRATCHPAD OFFSET
MASTER Tx MEMORY OR
TA1 [T7:T0], TA2 [T15:T8]
DS1921G SETS [E4:E0] =
MASTER Tx DATA BYTE
MASTER Rx CRC-16 OF
WRITE SCRATCHPAD?
SCRATCHPAD OFFSET
AND CLEARS (PF, AA)
MASTER Tx RESET?
MASTER Tx RESET?
MASTER Tx RESET?
OFFSET = 11111b?
MASTER Rx "1"s
DS1921G SETS
DS1921G SETS
SCRATCHPAD
MASTER Tx
EMCLR = 0
0Fh
Y
N
Y
N
N
BYTE WRITTEN?
N
Y
PARTIAL
FLOWCHART (FIGURE 13)
N
TO ROM FUNCTIONS
FLOWCHART (FIGURE 13)
FROM ROM FUNCTIONS
Y
PF = 1
SCRATCHPAD
INCREMENTS
DS1921G
OFFSET
N
Y
SCRATCHPAD OFFSET = [T4:T0]
E/S BYTE, AND DATA STARTING
MASTER Rx DATA BYTE FROM
COMMAND, ADDRESS, DATA,
MASTER Rx ENDING OFFSET
AT THE TARGET ADDRESS
TA1 [T7:T0], TA2 [T15:T8]
MASTER Rx CRC-16 OF
SCRATCHPAD OFFSET
READ SCRATCHPAD?
WITH DATA STATUS
MASTER Tx RESET?
MASTER Tx RESET?
OFFSET = 11111b?
MASTER Rx "1"s
DS1921G SETS
DS1921G SETS
SCRATCHPAD
MASTER Rx
EMCLR = 0
(E/S)
AAh
Y
N
Y
N
N
Y
MASTER Rx "1"s
N
N
DS1921G COPIES SCRATCHPAD
TA1 [T7:T0], TA2 [T15:T8]
COPY SCRATCHPAD
MASTER Tx RESET?
MASTER Tx RESET?
DATA TO MEMORY
AUTHORIZATION
DS1921G Tx "0"
DS1921G Tx "1"
DS1921G SETS
CODE MATCH?
MASTER Tx
MASTER Tx
EMCLR = 0
COPYING
FINISHED
E/S BYTE
AA = 1
55h
Y
Y
Y
N
Y
N
N
Y
MASTER Tx RESET?
MASTER Rx "1"s
Y
FROM FIGURE 10b
TO FIGURE 10b
N