AT88SC0404C-PI Atmel, AT88SC0404C-PI Datasheet - Page 30

• Manufacturer Part Number: AT88SC0404C-PI
• Manufacturer: Atmel

Specifications of AT88SC0404C-PI

• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Package Type: PDIP
• Mounting: Through Hole
• Pin Count: 8
• Operating Temperature Classification: Industrial
• Lead Free Status / RoHS Status: Not Compliant

7.3.
5211C–SMIC–01/10
Atmel AT88SC0104/0204/0404/0808/1616/3216/6416/12816/25616C
Command Format
Most Atmel
write command is characterized by a zero in the LSB of the first byte (device address). The numbers of word address
bytes in a TWI write command will vary depending on the size of the memory being addressed. All bytes whether part
of the command or data are generated by the host and sent to the memory device that will acknowledge each byte.
Figure 10. TWI Write Command
All CryptoMemory commands will have a zero for the LSB of the first byte. All CryptoMemory commands will have
4-bytes used for defining the command and addressing the memory. All but the CryptoMemory read commands will
send an additional 0- to 128-bytes of data following the four command bytes. These commands comply with the format
of a TWI write command.
The CryptoMemory read commands (Read User Zone, System Read) do not comply with the format of a TWI write or
read command. The CryptoMemory read command looks like a TWI write command (LSB of the first byte = 0) but after
the fourth byte of the command the CryptoMemory device will begin to send data back on the bus. The number of bytes
sent by CryptoMemory will be equal to the value of N.
Figure 11. CryptoMemory Read Command
The response of CryptoMemory will cause contention with the host on a standard TWI bus. Typically CryptoMemory
cannot be used on a standard TWI bus but requires a modified TWI protocol to account for the unique read command
format.
R
S
T
A
T
S
A
R
T
T
Command
Address
xxxx 0x10
xxxx xxx0
Device
®
CryptoMemory
C
C
A
K
A
K
Address 1
Address 1
xxxx xxxx
xxxx xxxx
Word
®
commands have the same format as a two-wire interface (TWI) write command. The TWI
C
A
C
K
A
K
Address 2
Address 2
xxxx xxxx
xxxx xxxx
Word
C
A
C
K
A
K
xxxx xxxx
xxxx xxxx
N
N
C
C
A
K
A
K
d7--- ---d0
d7--- ---d0
Data
Data
A
C
K
A
C
K
Data x N
Data X N
d7--- ---d0
d7--- ---d0
N
C
A
K
A
C
K
O
O
S
P
S
P
T
T
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