X46402V8-3.1 XICOR [Xicor Inc.], X46402V8-3.1 Datasheet - Page 9

• Manufacturer Part Number: X46402V8-3.1
• Description: Dual Voltage CPU Supervisor with 64K Password Protected EEPROM
• Manufacturer: XICOR [Xicor Inc.]

X46402
Figure 9. Definition of Start and Stop Conditions
Acknowledge
Acknowledge is a software convention used to indicate
successful data transfer. The transmitting device, either
master or slave, will release the bus after transmitting
eight bits. During the ninth clock cycle the receiver will
pull the SDA line LOW to acknowledge that it received
the eight bits of data.
The X46402 will respond with an acknowledge after rec-
ognition of a start condition and its slave address. If both
the device and a write condition have been selected, the
X46402 will respond with an acknowledge after the
receipt of each subsequent eight-bit word.
Table 3. X46402 Instruction Set
Notes: Illegal command codes will be disregarded. The part will respond with a “no-ACK” to the illegal byte and then return to the standby mode.
after Start
1000 0000
1000 1000
1001 0000
1001 1000
1010 0000
1010 1000
1011 0000
1011 1000
1100 0000
1100 1000
1101 1000
1110 1000
1111 0000
1st Byte
SCL
SDA
Start Condition
High Address
High Address
High Address
High Address
High Address
High Address
Password
0000 0000
0000 0000
0000 0000
0000 0000
0000 0000
1st Byte
not used
not used
All the rest
after
Low address
Low address
Low address
Low address
Low address
Low address
Password
0000 0000
0000 0000
0000 0000
0000 0000
0000 0000
2nd Byte
not used
not used
after
Stop Condition
ACK Polling command (Ends Password operation)
Reset Device Command (Resets Tamper bit)
No-Password Memory Array Read
No-Password Memory Array Write
Change Memory Read Password
Change Memory Write Password
Password Memory Array Read
Password Memory Array Write
Change OTP Read Password
Change OTP Write Password
9
Command Description
Change Reset Password
Read Device ID Command
A special, non-password protected command reads the
device ID. The device ID is a 32 bit identification code
that can be generic or tailored to the needs of an individ-
ual company. The last of the 32 bits indicates whether
the device has been tampered with by an unauthorized
user attempting to enter invalid passwords.
Reset Device Command
The Reset Device command resets the tamper bit, clears
the tamper counter and removes the tamper “lock”
(allowing the device to accept commands). However, the
Reset Device command does not clear any memory
array area.
OTP Read
OTP Write
Reserved
Preliminary Information
Password used
Memory Read
Memory Write
Memory Read
Memory Write
OTP Read
OTP Read
OTP Write
OTP Write
Reset
Reset
None
None
None